Your blood contains red blood cells (RBC), white blood cells (WBC), and platelets. Blood count tests measure the number and types of cells in your blood. Blood count tests help doctors check for certain diseases and conditions. Learn about blood count tests, like the complete blood count (CBC).
Blood Flow in An Artery
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Blood Count Tests
Complete blood count and differential
Image by SpicyMilkBoy/Wikimedia
Complete blood count and differential
Illustration of complete blood count and differential (hemogram, full blood exam, leukogram etc.) test results with blood specimen in EDTA tube. N.B. these are my own CBC and diff results so no patient confidentiality issues. Symbol key: CBC, complete blood cell count; WBC, white blood cell count (leukocyte count); RBC, red blood cell count (erythrocyte count); HGB, hemoglobin level; HCT, hematocrit; MCV, mean corpuscular volume; MCH, mean corpuscular hemoglobin (per erythrocyte); MCHC, mean corpuscular hemoglobin concentration; RDW-CV, red blood cell distribution width–coefficient of variation; PLT, platelet count (thrombocyte count); MPV, mean platelet volume; NEUT, neutrophil count; LYMPH, lymphocyte count; MONO, monocyte count; EO, eosinophil count; BASO, basophil count; IG, immature granulocyte count; NRBC, nucleated red blood cell count; EDTA, ethylenediaminetetraacetic acid, a preservative that makes the blood sample last long enough to be processed (it inhibits coagulation by chelating calcium ions).
Image by SpicyMilkBoy/Wikimedia
Blood Count Tests
Your blood contains red blood cells (RBC), white blood cells (WBC), and platelets. Blood count tests measure the number and types of cells in your blood. This helps doctors check on your overall health. The tests can also help to diagnose diseases and conditions such as anemia, infections, clotting problems, blood cancers, and immune system disorders.
Specific types include tests for
RBC - the numbers, size, and types of RBC in the blood
WBC - the numbers and types of WBC in the blood
Platelets - the numbers and size of the platelets
Hemoglobin - an iron-rich protein in red blood cells that carries oxygen
Hematocrit - how much space red blood cells take up in your blood
Reticulocyte count - how many young red blood cells are in your blood
Mean corpuscular volume (MCV) - the average size of your red blood cells
The complete blood count (CBC) includes most or all of these. The CBC is one of the most common blood tests.
Source: National Heart, Lung, and Blood Institute (NHLBI)
Additional Materials (1)
Red blood cell
A single drop of blood contains millions of red blood cells which are constantly traveling through the body to deliver oxygen and remove waste. The concave shape of a RBC increases the cells' surface area, which allows them to distribute more oxygen to the body's cells. The shape also enables the cells to bunch together more compactly, helping them travel through the bloodstream more efficiently. Manufactured in the bone marrow, RBCs are continuously produced and broken down. They live for about 120 days in the circulatory system.
Image by TheVisualMD
Red blood cell
TheVisualMD
Composition of Blood
Blood Components
Image by TheVisualMD
Blood Components
This image highlights the vital components of blood: 55% plasma Plasma is the liquid river that transports every blood cell to its destination. Oxygen-carrying RBCs couldn't move through arteries, veins and capillaries without it. Even though it is a watery, almost clear fluid, plasma contains many important substances, including blood-clotting agents called platelets and protective proteins called antibodies which help us fight infection. When the clotting agents are removed from blood plasma, it is called serum, which is essential in many life-saving medical situations such as transplant surgery and trauma. <1% white blood cells (wbcs or leukocytes) Some leukocytes are produced in the bone marrow, while others are generated in lymph nodes scattered throughout the body. They are far less numerous than their sister RBCs, but leukocytes are the bedrock of the immune system and are the body's front line of defense. Different types of leukocytes fight infections in different ways. Some target bacterial or fungal infections, while others respond to parasitic threats or allergic reactions. <1% platelets Platelets perform the vital function of clotting blood at wound sites. They are small, even in comparison to the other cells of your blood, but they pack a wallop when it comes to healing a scrape or staunching a more serious wound. When you cut yourself shaving, platelets arrive on the scene like your personal emergency medical team, creating a natural bandage of clotted blood, which eventually forms a scab. 45% red blood cells rbcs or erythrocytes) RBCs are produced in the bone marrow and perform the fundamental task of delivering oxygen to all of the body's cells. The vial is an example of the hematocrit, one of many tests that make up the complete blood count (CBC). Hematocrit measures the volume of RBCs in your blood. A normal hematocrit reading for women is between 36 to 44 percent; for men it's 41 to 50 percent.
Image by TheVisualMD
Composition of Blood
You have probably had blood drawn from a superficial vein in your arm, which was then sent to a lab for analysis. Some of the most common blood tests—for instance, those measuring lipid or glucose levels in plasma—determine which substances are present within blood and in what quantities. Other blood tests check for the composition of the blood itself, including the quantities and types of formed elements.
One such test, called a hematocrit, measures the percentage of RBCs, clinically known as erythrocytes, in a blood sample. It is performed by spinning the blood sample in a specialized centrifuge, a process that causes the heavier elements suspended within the blood sample to separate from the lightweight, liquid plasma (image). Because the heaviest elements in blood are the erythrocytes, these settle at the very bottom of the hematocrit tube. Located above the erythrocytes is a pale, thin layer composed of the remaining formed elements of blood. These are the WBCs, clinically known as leukocytes, and the platelets, cell fragments also called thrombocytes. This layer is referred to as the buffy coat because of its color; it normally constitutes less than 1 percent of a blood sample. Above the buffy coat is the blood plasma, normally a pale, straw-colored fluid, which constitutes the remainder of the sample.
The volume of erythrocytes after centrifugation is also commonly referred to as packed cell volume (PCV). In normal blood, about 45 percent of a sample is erythrocytes. The hematocrit of any one sample can vary significantly, however, about 36–50 percent, according to gender and other factors. Normal hematocrit values for females range from 37 to 47, with a mean value of 41; for males, hematocrit ranges from 42 to 52, with a mean of 47. The percentage of other formed elements, the WBCs and platelets, is extremely small so it is not normally considered with the hematocrit. So the mean plasma percentage is the percent of blood that is not erythrocytes: for females, it is approximately 59 (or 100 minus 41), and for males, it is approximately 53 (or 100 minus 47).
Composition of Blood
The cellular elements of blood include a vast number of erythrocytes and comparatively fewer leukocytes and platelets. Plasma is the fluid in which the formed elements are suspended. A sample of blood spun in a centrifuge reveals that plasma is the lightest component. It floats at the top of the tube separated from the heaviest elements, the erythrocytes, by a buffy coat of leukocytes and platelets. Hematocrit is the percentage of the total sample that is comprised of erythrocytes. Depressed and elevated hematocrit levels are shown for comparison.
Source: CNX OpenStax
Additional Materials (8)
What Are the Components of Blood?
Video by Seeker/YouTube
The Components of Blood and Their Importance
Video by American Society of Hematology/YouTube
Human Blood Video | Blood Components | Blood Cells
Shows the components of blood: erythrocytes ( red blood cells) leukocytes (white blood cells), and platelets as a large amount of blood rushes toward a stationary camera
Video by TheVisualMD
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Red Blood Cells Carry Oxygen
This video focuses on one of the main components of blood, the red blood cell and its function to carry oxygen. The video begins with revealing the red blood cells and the heart that pumps the oxygenated blood to the rest of the body. Hemoglobin is the protein molecule found in these red blood cells that enable blood to transport oxygen. If the blood's capacity to transport oxygen to the tissues is reduced due to a decrease in the number of red blood cells, anemia may occur.
Video by TheVisualMD
This browser does not support the video element.
Complete Blood Count, and Baselining Your Health
Video Topics : Our lifeblood consists of many components and a complete blood count (CBC) includes measurements of the fundamental elements. The largest categories are red and white blood cells (RBCs and WBCs) and cell fragments called platelets, which play roles in blood clotting. There are 20-30 trillion red blood cells in the body of an adult, each with a lifespan of about 100 days (RBCs contain an iron-containing protein called hemoglobin that enables them to carry oxygen to tissues throughout the body and then return carbon dioxide to the lungs). WBCs are in the front lines in the body's ongoing fight against harmful viruses, bacteria and even fungus; when a pathogen enters the body, WBCs mobilize in a coordinated defense response to eliminate, neutralize or mark the invader for destruction. The liquid portion of blood is called plasma and it carries nutrients, electrolytes, waste products, and hormones.
Video by TheVisualMD
Composition of Blood
The cellular elements of blood include a vast number of erythrocytes and comparatively fewer leukocytes and platelets. Plasma is the fluid in which the formed elements are suspended. A sample of blood spun in a centrifuge reveals that plasma is the lightest component. It floats at the top of the tube separated from the heaviest elements, the erythrocytes, by a buffy coat of leukocytes and platelets. Hematocrit is the percentage of the total sample that is comprised of erythrocytes. Depressed and elevated hematocrit levels are shown for comparison.
Image by CNX Openstax
7:56
What Are the Components of Blood?
Seeker/YouTube
0:52
The Components of Blood and Their Importance
American Society of Hematology/YouTube
3:18
Human Blood Video | Blood Components | Blood Cells
Also called: Hematrocit, HCT, Crit, Packed Cell Volume, PCV
Hematocrit is a blood test that measures how much of a person's blood is made up of red blood cells. Hematocrit levels that are too high or too low can be a sign of a blood disorder, dehydration, or other medical conditions that affect your blood.
Hematocrit Blood Test
Also called: Hematrocit, HCT, Crit, Packed Cell Volume, PCV
Hematocrit is a blood test that measures how much of a person's blood is made up of red blood cells. Hematocrit levels that are too high or too low can be a sign of a blood disorder, dehydration, or other medical conditions that affect your blood.
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A hematocrit level below the normal range, meaning the person has too few red blood cells, is called anemia.
Related conditions
A hematocrit test is a blood test that measures how much of your blood is made up of red blood cells. Red blood cells carry oxygen from your lungs to the rest of your body. The other parts of your blood include white blood cells (to help fight infection), platelets (to help make blood clots to stop bleeding), and a liquid called plasma.
Hematocrit levels that are too high or too low can be a sign of a blood disorder, dehydration, or other medical conditions that affect your blood.
Other names: HCT, packed cell volume, PCV, Crit; H and H (Hemoglobin and Hematocrit)
A hematocrit test is often part of a complete blood count (CBC). A CBC is a common blood test that measures the different parts of your blood. It is used to check your general health. It may also be used to help diagnose blood disorders, including anemia, a condition in which you don't have enough red blood cells, and polycythemia, an uncommon disorder in which you have too many red blood cells and your blood becomes too thick.
Your health care provider may order a hematocrit test as part of your regular checkup or to monitor your health if you are being treated for cancer or have an ongoing health condition. Your provider may also order this test if you have symptoms of a red blood cell disorder, such as anemia or polycythemia:
Symptoms of anemia (too few red blood cells) may include:
Shortness of breath
Weakness or fatigue
Headache
Dizziness
Arrhythmia (a problem with the rate or rhythm of your heartbeat)
Symptoms of polycythemia (too many red blood cells) may include:
Headache
Feeling light-headed or dizzy
Shortness of breath
Weakness or fatigue
Skin symptoms such as itching after a shower or bath, burning, or a red face
Heavy sweating, especially during sleep
Blurred or double vision and blind spots
Bleeding gums and heavy bleeding from small cuts
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
You don't need any special preparations for a hematocrit test. If your provider has ordered more tests on your blood sample, you may need to fast (not eat or drink) for several hours before the test. Your provider will let you know if there are any special instructions to follow.
There is very little risk to having a hematocrit test or other type of blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
Your hematocrit test results are reported as a number. That number is the percentage of your blood that's made of red blood cells. For example, if your hematocrit test result is 42, it means that 42% of your blood is red blood cells and the rest is white blood cells, platelets, and blood plasma.
A hematocrit level that's lower than normal may be a sign that:
Your body doesn't have enough red blood cells (anemia). There are many types of anemia that can be caused by different medical conditions.
Your body is making too many white blood cells, which may be caused by:
Bone marrow disease
Certain cancers, including leukemia, lymphoma, multiple myeloma, or cancers that spread to the bone marrow from other parts of the body
A hematocrit level that's higher than normal may be a sign that:
Your body is making too many red blood cells, which may be caused by:
Lung disease
Congenital heart disease
Heart failure
Polycythemia
Your blood plasma level is too low, which may be caused by:
Dehydration, the most common cause of a high hematocrit
Shock
If your results are not in the normal range, it doesn't always mean that you have a medical condition that needs treatment. Living at high altitudes where there's less oxygen in the air may cause a high hematocrit. That's because your body responds to low oxygen levels by making more red blood cells so that you get the oxygen you need.
Pregnancy can cause a low hematocrit. That's because the body has more fluid than normal during pregnancy, which decreases the percentage that's made of red blood cells.
To learn what your test results mean, talk with your provider.
Normal hematocrit levels will be different depending on your sex, age, and the altitude where you live. Ask your provider what hematocrit level is normal for you.
Hematocrit Test: MedlinePlus Medical Test [accessed on Jan 20, 2024]
Hematocrit: MedlinePlus Medical Encyclopedia [accessed on Jan 20, 2024]
Hematrocit Blood Test - Testing.com. Sep 13, 2022 [accessed on Jan 20, 2024]
Normal reference ranges can vary depending on the laboratory and the method used for testing. You must use the range supplied by the laboratory that performed your test to evaluate whether your results are "within normal limits."
Additional Materials (30)
This browser does not support the video element.
Complete Blood Count, and Baselining Your Health
Video Topics : Our lifeblood consists of many components and a complete blood count (CBC) includes measurements of the fundamental elements. The largest categories are red and white blood cells (RBCs and WBCs) and cell fragments called platelets, which play roles in blood clotting. There are 20-30 trillion red blood cells in the body of an adult, each with a lifespan of about 100 days (RBCs contain an iron-containing protein called hemoglobin that enables them to carry oxygen to tissues throughout the body and then return carbon dioxide to the lungs). WBCs are in the front lines in the body's ongoing fight against harmful viruses, bacteria and even fungus; when a pathogen enters the body, WBCs mobilize in a coordinated defense response to eliminate, neutralize or mark the invader for destruction. The liquid portion of blood is called plasma and it carries nutrients, electrolytes, waste products, and hormones.
Video by TheVisualMD
Vial of Centrifuged Blood
Blood is made up of red and white blood cell (as well as platelets), suspended in a liquid known as blood plasma. Plasma, which makes up 55% of our blood's volume, is a clear liquid (mainly water) that transports food molecules, hormones, waste as well as a wide range of dissolved chemicals. Red cells, which normally make up 40-50% of total blood volume, are produced continuously in our bone marrow at the rate of about 2-3 million cells per second. White cells make up a very small part of blood's volume-normally only about 1% in healthy people. This image shows two vials of centrifuged blood. The left vial shows healthy amount of red blood cells in female (36-44%) ; The right vial shows healthy amount of red blood cells in male (41-50%). The hematocrit (along with the hemoglobin test) is the central test to diagnosing anemia in that it indicates the amount of RBCs in the blood.
Image by TheVisualMD
Red Blood Cells, Bone Marrow
A skeleton may have a dry and lifeless Halloween image, but bone is actually dynamic, living tissue. Bone is not uniformly solid; within its interior is a network of cavities that house blood vessels and marrow. Bone marrow, particularly in larger bones, is where stem cells give rise to red blood cells (erythrocytes) as well as white blood cells (leukocytes) and blood clotting agents (platelets). As the source of blood cells, the bone marrow is critical to health. Disease or damage to bone marrow can result in either too many or too few blood cells.
Hematocrit Nursing Considerations, Normal Range, Nursing Care, Lab Values Nursing
Video by NURSINGcom/YouTube
Hematocrit, Dehydration
Blood is composed of cells (primarily red blood cells, but also white blood cells and cell fragments called platelets) along with a liquid portion known as plasma. The ratio of the volume of red blood cells to the volume of plasma is an important health indicator and is known as the hematocrit. The most common cause of a high hematocrit is dehydration, which is usually temporary and easily remedied by increasing fluid intake, thereby restores the balance between RBCs and blood plasma volume.
Image by TheVisualMD
Hematocrit, Anemia
Blood is composed of cells (primarily red blood cells, but also white blood cells and cell fragments called platelets) along with a liquid portion known as plasma. The ratio of the volume of red blood cells to the volume of plasma is an important health indicator and is known as the hematocrit. A low hematocrit usually indicates anemia, which occurs when red blood cells are being either destroyed too quickly or produced too slowly; with fewer red blood cells, less oxygen is delivered to body tissues.
Image by TheVisualMD
Vial of Blood for Hematocrit Test
This image is a vial of blood that has been centrifuged (and thus separated) to determine hematocrit. This vial shows, from top to bottom, 55% plasma, <1% white blood cells, <1% platelets , 45% red blood cells. Hematocrit measures how much of the blood, by volume, is taken up by RBCs. A normal range for hematocrit is 41 to 50 percent in men and 36 to 44 percent in women. In many cases, a reading below the normal range for hematocrit will lead to a diagnosis of CKD-related anemia.This other diagnostic test is the hemoglobin test, which measures the amount of hemoglobin molecules in the blood and is a good indicator of the body's ability to carry oxygen throughout the body.
Image by TheVisualMD
Hematocrit: Bone Marrow
Bone marrow produces about 2 million red blood cells (RBCs) a second to maintain a healthy hematocrit. Many conditions, including kidney disease, chemotherapy, and dietary deficiencies, can reduce RBC production, while others can result in too many RBCs.
Image by TheVisualMD
Hematocrit: Blood Cells
The hematocrit is another way to look at the health of red blood cells (RBCs). Blood is composed of cells (primarily RBCs) and a liquid portion called plasma. The proportions of RBCs and plasma must be kept in balance and this is what the hematocrit measures.
Image by TheVisualMD
Blood
Components of Blood : Blood is mostly made up of plasma and red and white blood cells. But it also contains many other substances as well, like platelets, hormones, nutrients such as glucose, and fats like cholesterol. Blood is the fluid of life, transporting oxygen from the lungs to body tissue and carbon dioxide from body tissue to the lungs.
Image by TheVisualMD
Hematocrit
Hematocrit Blood Vials : If you are at risk for cardiovascular disease, your doctor may order a cholesterol and triglyceride level test as well as a complete blood count (CBC). Abnormal results may be the first clue in determining risk of and in diagnosing cardiovascular disease.
Image by TheVisualMD
Blood Smear Showing Reduced Red Blood Cell Count
Individual blood cells were first detected and described in the 17th century. Later, red blood cells (RBCs) were counted manually from a blood smear, a thin film of blood prepared on a glass slide and examined under a microscope (blood analysis is now automated, though smears are still used to detect visible abnormalities and to check or confirm the results of other tests). Anemia results when there are too few RBCs in circulation because they are being destroyed too quickly or produced too slowly. Anemia can be temporary or long term and range from mild to severe. Folate (also known as vitamin B9) is necessary for red blood cell production and the prevention of anemia, as well as the metabolism of carbohydrates. But folate also plays key roles in the synthesis and maintenance of DNA and is especially important in cell division and growth in fetal development (deficiencies of the vitamin in pregnancy is a common cause of birth defects). Pernicious anemia is a disorder in which the body's loses its ability to utilize folate and vitamin B12.
Image by TheVisualMD
Blood Smear Showing Normal Red Blood Cell Count
Individual blood cells were first detected and described in the 17th century. Later, red blood cells were counted manually from a blood smear, a thin film of blood prepared on a glass slide and examined under a microscope. Blood analysis is now automated, though blood smears are still used to detect visible abnormalities and to check or confirm the results of other tests. There are normally between 4.2-5.8 million red blood cells per microliter (about a drop), which means there are 20-30 trillion red blood cells circulating through the body of an adult.
Image by TheVisualMD
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Red Blood Cells Carry Oxygen
This video focuses on one of the main components of blood, the red blood cell and its function to carry oxygen. The video begins with revealing the red blood cells and the heart that pumps the oxygenated blood to the rest of the body. Hemoglobin is the protein molecule found in these red blood cells that enable blood to transport oxygen. If the blood's capacity to transport oxygen to the tissues is reduced due to a decrease in the number of red blood cells, anemia may occur.
Video by TheVisualMD
Components of Blood
Components of Blood : Our blood is composed of many different components, the largest categories being red and white blood cells (blood-clotting platelets are another key component) and the liquid portion known as blood plasma. A Complete Blood Count (CBC) includes several of the most basic, yet important, measurements of these components.
Image by TheVisualMD
Blood and Related Conditions
Blood and Related Conditions : Anemia results when there are too few red blood cells circulating in the bloodstream to deliver adequate oxygen to body tissues. There are different types and causes of anemia, including malnutrition, chronic bleeding, and diseases that result in red blood cells either being destroyed too quickly or produced too slowly.
Image by TheVisualMD
Pellet of Lymphocyte Cells Created in the Centrifuge
This photograph shows Wendy Watford, Ph.D. holding a test tube containing isolated lymphocyte cells. The cells were spun in a centrifuge to create a pellet at the bottom of the test tube. The cells will be labeled with CFSE dye, which will stain the membranes of the cells. After culturing the cells for three days she will determine the number of cell divisions that have taken place by measuring the dilution of the CFSE dye. The purpose of the work is to measure the proliferation of lymphocytes under various conditions. The principal investigator for this work is John J. O’Shea, M.D., NIAMS Scientific Director.
Image by NIAMS/Photographer: Rhoda Baer
Red Blood Cells
Digital holographic microscopy (DHM) image of red blood cells.
Image by Egelberg (talk)
Test Tube
Between 5,000 and 8,000 blood serum, fecal, urine, viral and respiratory samples arrive six days a week from U.S. Air Force hospitals and clinics worldwide, as well as some other Department of Defense facilities, for analysis at the Epidemiology Laboratory Service, also known as the "Epi Lab" at the 711th Human Performance Wing’s United States Air Force School of Aerospace Medicine and Public Health at Wright Patterson AFB, Ohio.The lab is a Department of Defense reference laboratory offering clinical diagnostic, public health, and force health screening and testing. (U.S. Air Force photo by J.M. Eddins Jr.)
Image by U.S. Air Force photo by J.M. Eddins Jr.
Phlebotomy
This image was uploaded as part of Wiki Loves e-textbooks contest in Poland.
Image by Sean Michael Ragan
Red Blood Cells Carry Oxygen
This video focuses on one of the main components of blood, the red blood cell and its function to carry oxygen. The video begins with revealing the red blood cells and the heart that pumps the oxygenated blood to the rest of the body. Hemoglobin is the protein molecule found in these red blood cells that enable blood to transport oxygen. If the blood's capacity to transport oxygen to the tissues is reduced due to a decrease in the number of red blood cells, anemia may occur.
Image by TheVisualMD
Composition of Blood
Composition of Blood
Image by OpenStax College
Hematology | Hematocrit
Video by Ninja Nerd/YouTube
Erythrocyte indices (Hemoglobin, Hematocrit, MCV, MCH & MCHC) What Do These Lab Tests Mean?
Video by Medicosis Perfectionalis/YouTube
How to Interpret RBC Indices (e.g. hemoglobin vs. hematocrit, MCV, RDW)
Video by Strong Medicine/YouTube
Haematocrit or PCV
Video by LabsforLifeProject/YouTube
Packed cell volume/ Hematocrit
Video by Pathology Simplified/YouTube
Fetal hemoglobin and hematocrit | Human anatomy and physiology | Health & Medicine | Khan Academy
5 Amazing Facts about the Red Blood Cell : Your kidneys regulate red blood cell production. Red blood cells transport oxygen from the lungs to all the tissues of the body that require it. The kidneys measure oxygen levels in the blood. When they detect below-normal oxygen levels, the kidneys release the hormone erythropoietin (EPO). EPO travels from the kidneys to your bone marrow, where about 95% of blood cells are made. There, EPO binds to receptors in the stem cell walls. This triggers a series of events inside the stem cells that instructs their DNA to transform them into red blood cells. People with kidney failure become anemic because the kidneys no longer make enough EPO to stimulate red blood cell production.
Image by TheVisualMD
Making Red Blood Cells
Most EPO production takes place in the renal cortex, in the upper portion of your kidneys. EPO production is stimulated when oxygen levels in the renal vasculature (blood vessels) drop. EPO travels from your kidneys to your bone marrow, where it binds to receptors in the walls of stem cells. This triggers a series of events inside the stem cells that instructs their DNA to transform them into red blood cells.
Some people lack sufficient amounts of EPO. Fortunately, a synthetic version of EPO is available that can be taken through subcutaneous (under the skin) injection, several times a week. Longer-acting EPO may also be given intravenously every other week.
Source: TheVisualMD
Additional Materials (17)
Erythropoiesis in Bone Marrow
Bone is dynamic, living tissue; within its interior is a network of cavities that house blood vessels and marrow. Bone marrow, particularly in larger bones, is where stem cells give rise to red blood cells (erythrocytes) as well as white blood cells (leukocytes) and blood clotting agents (platelets). Specialized cells in the kidney, which are sensitive to low oxygen levels, produce a hormone called erythropoietin (EPO), which in turn promotes the production of red blood cells. The boost in red blood cell production (erythropoiesis) in turn increases the oxygen-carrying capacity of the blood.
Image by TheVisualMD
Making Red Blood Cells
Most EPO production takes place in the renal cortex, in the upper portion of your kidneys. EPO production is stimulated when oxygen levels in the renal vasculature (blood vessels) drop. EPO travels from your kidneys to your bone marrow, where it binds to receptors in the walls of stem cells. This triggers a series of events inside the stem cells that instructs their DNA to transform them into red blood cells.
Image by TheVisualMD
EPO Binding to its Receptor
Bone marrow, particularly in larger bones, is where stem cells give rise to red blood cells (erythrocytes) as well as white blood cells (leukocytes) and blood clotting agents (platelets). Specialized cells in the kidney, which are sensitive to low oxygen levels, produce a hormone called erythropoietin (EPO), which in turn promotes the production of red blood cells (erythropoiesis). EPO travels from the kidneys to the bone marrow, where it binds to receptors in the walls of stem cells. The boost in red blood cell production in turn increases the oxygen-carrying capacity of the blood.
Image by TheVisualMD
Drawing of diseased kidney that fails to produce enough erythropoietin to stimulate red blood cells, resulting in anemia
None
Image by NIDDK Image Library
Erythropoietin (EPO) Molecule
EPO intimately connects the blood and kidneys. When the kidneys detect low oxygen levels in the blood as it flows through them, they produce EPO. Once this chemical messenger arrives in the bone marrow, the stem cells there begin to produce RBCs in response.
Image by TheVisualMD
Tubule of Nephron Revealing Many Red Blood Cell
This image shows the cut distal convoluted tubule of nephron with surrounding capillaries cut to reveal many red blood cells and healthy amounts of Erythopoeitin, EPO, (yellow particles). Erythropoeitin, EPO, is produced by the endothelial cells of the capillaries and the fibroblasts in the interstitial tissue surrounding the distal tubules. Normally, the kidneys produce EPO in response to low oxygen levels in order to stimulate red blood cell production in the bone marrow. A normal amount of red blood cells allows for the delivery of an adequate supply of oxygen.
Image by TheVisualMD
Kidney and Stem Cell Creating Red Blood Cell
Kidney and Stem Cell Creating Red Blood Cell : We are used to thinking of our kidneys mostly as hardworking filters that rid our bodies of wastes and excess water. But the kidneys are also constantly monitoring and adjusting levels of key substances in the blood, depending on what the body needs. Specialized cells in the kidney that are very sensitive to low oxygen levels, for example, produce a hormone called erythropoietin (EPO), which in turn promotes the production of red blood cells in the bone marrow. The boost in red blood cells increases the oxygen-carrying capacity of the blood.
Image by TheVisualMD
Hematopoietic System of Bone Marrow
Hemopoiesis is the proliferation and differentiation of the formed elements of blood.
Image by CNX Openstax
Blood, Part 2 - There Will Be Blood: Crash Course A&P #30
Video by CrashCourse/YouTube
The Role of Red Blood Cells in Anemia
Video by American Society of Hematology/YouTube
How do your kidneys work? - Emma Bryce
Video by TED-Ed/YouTube
Haematology - Red Blood Cell Life Cycle
Video by Armando Hasudungan/YouTube
This browser does not support the video element.
Red Blood Cell Production
Red blood cell production or erythropoiesis is the process by which red blood cells are formed.
Video by TheVisualMD
Oxygen’s surprisingly complex journey through your body - Enda Butler
Video by TED-Ed/YouTube
This browser does not support the video element.
Red Blood Cell and Erythropoietin Passing in Vessel
Animation of red blood cells and erythropoietin passing in a vessel. The camera angle is a close up view within the vessel and the rbc's and erythropoietin flow by quickly.
Video by TheVisualMD
Red Blood Cell Production
Red blood cell production or erythropoiesis is the process by which red blood cells are formed.
Image by TheVisualMD
Hematology | Erythropoiesis: Red Blood Cell Formation: Part 1
Video by Ninja Nerd/YouTube
Erythropoiesis in Bone Marrow
TheVisualMD
Making Red Blood Cells
TheVisualMD
EPO Binding to its Receptor
TheVisualMD
Drawing of diseased kidney that fails to produce enough erythropoietin to stimulate red blood cells, resulting in anemia
NIDDK Image Library
Erythropoietin (EPO) Molecule
TheVisualMD
Tubule of Nephron Revealing Many Red Blood Cell
TheVisualMD
Kidney and Stem Cell Creating Red Blood Cell
TheVisualMD
Hematopoietic System of Bone Marrow
CNX Openstax
10:01
Blood, Part 2 - There Will Be Blood: Crash Course A&P #30
CrashCourse/YouTube
1:04
The Role of Red Blood Cells in Anemia
American Society of Hematology/YouTube
3:55
How do your kidneys work? - Emma Bryce
TED-Ed/YouTube
6:14
Haematology - Red Blood Cell Life Cycle
Armando Hasudungan/YouTube
5:22
Red Blood Cell Production
TheVisualMD
5:10
Oxygen’s surprisingly complex journey through your body - Enda Butler
TED-Ed/YouTube
0:12
Red Blood Cell and Erythropoietin Passing in Vessel
TheVisualMD
Red Blood Cell Production
TheVisualMD
29:51
Hematology | Erythropoiesis: Red Blood Cell Formation: Part 1
Ninja Nerd/YouTube
White Blood Cells
White Blood Cells Rotation
Image by TheVisualMD
White Blood Cells Rotation
This rotational interactive features five white blood cells. At the top left is a neutrophil (purple nucleus); center is a Monocyte-macrophage (orange nucleus); top right is a Lymphocyte (red nucleus); bottom left a Basophil (green nucleus); and bottom right an Eosinophil (yellow nucleus). These molecules are all part of a white blood cell count test. A white blood cell count is an important measure of this key component of the immune system; when the body is under attack, more WBCs are produced. White blood cells (also called leukocytes or WBCs) are in the front lines in the fight against harmful viruses, bacteria and even fungus. A white blood cell count is an important measure of this key component of the immune system; when the body is under attack, more WBCs are produced. Other factors, however, may also affect WBC counts, including allergies, chemotherapy, and other drugs, as well as leukemia.
Image by TheVisualMD
White Blood Cells
White blood cells, also called leukocytes (leuko = white), make up approximately one percent by volume of the cells in blood. The role of white blood cells is very different than that of red blood cells: they are primarily involved in the immune response to identify and target pathogens, such as invading bacteria, viruses, and other foreign organisms. White blood cells are formed continually; some only live for hours or days, but some live for years.
The morphology of white blood cells differs significantly from red blood cells. They have nuclei and do not contain hemoglobin. The different types of white blood cells are identified by their microscopic appearance after histologic staining, and each has a different specialized function. The two main groups, both illustrated in Figure 40.7 are the granulocytes, which include the neutrophils, eosinophils, and basophils, and the agranulocytes, which include the monocytes and lymphocytes.
Figure 40.7 (a) Granulocytes—including neutrophils, eosinophils and basophils—are characterized by a lobed nucleus and granular inclusions in the cytoplasm. Granulocytes are typically first-responders during injury or infection. (b) Agranulocytes include lymphocytes and monocytes. Lymphocytes, including B and T cells, are responsible for adaptive immune response. Monocytes differentiate into macrophages and dendritic cells, which in turn respond to infection or injury.
Figure 40.5 The cells and cellular components of human blood are shown. Red blood cells deliver oxygen to the cells and remove carbon dioxide. White blood cells—including neutrophils, monocytes, lymphocytes, eosinophils, and basophils—are involved in the immune response. Platelets form clots that prevent blood loss after injury.
Source: CNX OpenStax
Additional Materials (2)
Anthrax - How People Are Infected?
Neutrophil engulfing anthrax bacteria : Neutrophil (yellow) engulfing anthrax bacteria (orange), taken with a Leo 1550 scanning electron microscope. Scale bar is 5 micrometers.
Image by Volker Brinkmann
White Blood Cells (WBCs) | Your body’s Defense | Hematology
Video by Medicosis Perfectionalis/YouTube
Anthrax - How People Are Infected?
Volker Brinkmann
10:21
White Blood Cells (WBCs) | Your body’s Defense | Hematology
Medicosis Perfectionalis/YouTube
White Blood Count (WBC)
White Blood Count (WBC)
Also called: WBC, WBC Blood Test, White Blood Count, White Blood Cell Count, Leukocyte Count, Leukopenia Test, Leukocytosis Test
A white blood count measures the number of white cells in your blood. White blood cells are part of the immune system. A count that is too high or too low can indicate an infection, immune system disorder, or another health problem.
White Blood Count (WBC)
Also called: WBC, WBC Blood Test, White Blood Count, White Blood Cell Count, Leukocyte Count, Leukopenia Test, Leukocytosis Test
A white blood count measures the number of white cells in your blood. White blood cells are part of the immune system. A count that is too high or too low can indicate an infection, immune system disorder, or another health problem.
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A low white blood cell count, called leukopenia, can result from a number of conditions and diseases, such as immune deficiencies, severe infections, and bone marrow disorders, among others.
Related conditions
A white blood count measures the number of white cells in your blood. White blood cells are part of the immune system. They help your body fight off infections and other diseases.
When you get sick, your body makes more white blood cells to fight the bacteria, viruses, or other foreign substances causing your illness. This increases your white blood count.
Other diseases can cause your body to make fewer white blood cells than you need. This lowers your white blood count. Diseases that can lower your white blood count include some types of cancer and HIV/AIDS, a viral disease that attacks white blood cells. Certain medicines, including chemotherapy, may also lower the number of your white blood cells.
There are five major types of white blood cells:
Neutrophils
Lymphocytes
Monocytes
Eosinophils
Basophils
A white blood count measures the total number of these cells in your blood. Another test, called a blood differential, measures the amount of each type of white blood cell.
Other names: WBC count, white cell count, white blood cell count
A white blood count is most often used to help diagnose disorders related to having a high white blood cell count or low white blood cell count.
Disorders related to having a high white blood count include:
Autoimmune and inflammatory diseases, conditions that cause the immune system to attack healthy tissues
Bacterial or viral infections
Cancers such as leukemia and Hodgkin disease
Allergic reactions
Disorders related to having a low white blood count include:
Diseases of the immune system, such as HIV/AIDS
Lymphoma, a cancer of the bone marrow
Diseases of the liver or spleen
A white blood count can show if the number of your white blood cells is too high or too low, but it can't confirm a diagnosis. So it is usually done along with other tests, such as a complete blood count, blood differential, blood smear, and/or bone marrow test.
You may need this test if you have signs of an infection, inflammation, or autoimmune disease. Symptoms of infection include:
Fever
Chills
Body aches
Headache
Symptoms of inflammation and autoimmune diseases will be different, depending on the area of inflammation and type of disease.
You may also need this test if you have a disease that weakens your immune system or are taking medicine that lowers your immune response. If the test shows your white blood count is getting too low, your provider may be able to adjust your treatment.
Your newborn or older child may also be tested as part of a routine screening, or if they have symptoms of a white blood cell disorder.
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out.
To test children, a health care provider will take a sample from the heel (newborns and young babies) or the fingertip (older babies and children). The provider will clean the heel or fingertip with alcohol and poke the site with a small needle. The provider will collect a few drops of blood and put a bandage on the site.
You don't need any special preparations for a white blood count.
After a blood test, you may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
There is very little risk to your baby or child with a needle stick test. Your child may feel a little pinch when the site is poked, and a small bruise may form at the site. This should go away quickly.
A high white blood count may mean you have one of the following conditions:
A bacterial or viral infection
An inflammatory disease such as rheumatoid arthritis
An allergy
Leukemia or Hodgkin disease
Tissue damage from a burn injury or surgery
A low white blood count may mean you have one of the following conditions:
Bone marrow damage. This may be caused by infection, disease, or treatments such as chemotherapy.
Cancers that affect the bone marrow
An autoimmune disorder, such as lupus (or SLE)
HIV/AIDS
If you are already being treated for a white blood cell disorder, your results may show if your treatment is working or whether your condition has improved.
If you have questions about your results, talk to your health care provider.
White blood count results are often compared with results of other blood tests, including a blood differential. A blood differential test shows the amount of each type of white blood cell, such as neutrophils or lymphocytes. Neutrophils mostly target bacterial infections. Lymphocytes mostly target viral infections.
A higher than normal amount of neutrophils is known as neutrophilia.
A lower than normal amount is known as neutropenia.
A higher than normal amount of lymphocytes is known as lymphocytosis.
A lower normal amount is known as lymphopenia.
White Blood Count (WBC): MedlinePlus Medical Test [accessed on Jan 20, 2024]
WBC count: MedlinePlus Medical Encyclopedia [accessed on Jan 20, 2024]
White Blood Cell Count (WBC Blood Test) - Testing.com. Sep 28, 2022 [accessed on Jan 20, 2024]
Normal reference ranges can vary depending on the laboratory and the method used for testing. You must use the range supplied by the laboratory that performed your test to evaluate whether your results are "within normal limits."
Additional Materials (37)
White Blood Cell Count: Bone Marrow
Disease or damage to the bone marrow, caused by infection, cancer, radiation treatment, or chemotherapy can lower white blood cell count by impairing the marrow's ability to produce new white blood cells.
Image by TheVisualMD
White Blood Cells, Bone Marrow
Bone marrow is constantly producing blood cells, including white blood cells and red blood cells as well platelets, which are cell fragments important for blood clotting. Disease and disorders of the bone marrow can, in turn, affect the production of blood cells. Both cancer and cancer treatment (chemotherapy and radiation) can also have an impact on the bone marrow's ability to produce blood cells.
Image by TheVisualMD
This browser does not support the video element.
Complete Blood Count, and Baselining Your Health
Video Topics : Our lifeblood consists of many components and a complete blood count (CBC) includes measurements of the fundamental elements. The largest categories are red and white blood cells (RBCs and WBCs) and cell fragments called platelets, which play roles in blood clotting. There are 20-30 trillion red blood cells in the body of an adult, each with a lifespan of about 100 days (RBCs contain an iron-containing protein called hemoglobin that enables them to carry oxygen to tissues throughout the body and then return carbon dioxide to the lungs). WBCs are in the front lines in the body's ongoing fight against harmful viruses, bacteria and even fungus; when a pathogen enters the body, WBCs mobilize in a coordinated defense response to eliminate, neutralize or mark the invader for destruction. The liquid portion of blood is called plasma and it carries nutrients, electrolytes, waste products, and hormones.
Video by TheVisualMD
The Immune System Explained I – Bacteria Infection
Video by Kurzgesagt – In a Nutshell/YouTube
Immune Response to Bacteria
Video by NIAID/YouTube
Immunology - Adaptive Immune System
Video by Armando Hasudungan/YouTube
Immune System - Natural Killer Cell
Video by Kyle Thornthwaite/YouTube
Your Immune System: Natural Born Killer - Crash Course Biology #32
Video by CrashCourse/YouTube
White Blood Cell and Red Blood Cell
Medical visualization of blood cells. Depicted are numerous red blood cells and a single white blood cell.
Image by TheVisualMD
White Blood Cell and Red Blood Cell
Medical visualization of blood cells. Depicted are numerous red blood cells and a single white blood cell.
Image by TheVisualMD
Red Blood Cell and White Blood Cell
Visualization of red blood cells and a white blood cell
Image by TheVisualMD
Sensitive content
This media may include sensitive content
Blood cells (from left to right: erythrocyte, thrombocyte, leukocyte)
A single drop of blood contains millions of red blood cells, white blood cells, and platelets. One of each type is shown here, isolated from a scanning electron micrograph.
Image by Electron Microscopy Facility at The National Cancer Institute at Frederick (NCI-Frederick)
Bone structure
Anatomy of the bone. The bone is made up of compact bone, spongy bone, and bone marrow. Compact bone makes up the outer layer of the bone. Spongy bone is found mostly at the ends of bones and contains red marrow. Bone marrow is found in the center of most bones and has many blood vessels. There are two types of bone marrow: red and yellow. Red marrow contains blood stem cells that can become red blood cells, white blood cells, or platelets. Yellow marrow is made mostly of fat.
Image by Smart Servier website
Blood Cells
Formed Elements of Blood
Image by Blausen.com staff (2014). \"Medical gallery of Blausen Medical 2014\"
Phagocytosis - C-reactive protein (CRP) is a substance made by the liver that is released into the bloodstream by inflammation and infection as part of the body's immune response.
C-reactive protein (CRP) is a substance made by the liver that is released into the bloodstream by inflammation and infection as part of the body's immune response. White blood cells are also mobilized by the immune system and CRP is believed to enhance the activity of the white blood cells called macrophages. Each type of white blood cell has its own specialized immune functions; macrophages, for example, basically engulf and \"eat\" foreign invaders such as bacteria, viruses and fungi. Macrophages in the spleen and the liver weed out old and defective red blood cells and break them into recyclables (iron, heme, and some globin) and wastes (such as bilirubin). The bilirubin is then used by the liver to produce bile, which is stored in the gallbladder and released into the small intestine to aid digestion.
Image by TheVisualMD
White blood cells
Immune cells surrounding hair follicles in mouse skin. These hair follicles are home to a diverse array of commensal bacteria.
Image by NIAID
Neutrophil
Neutrophil function, relationship to disease, and location in the human body. Credit: NIAID
Image by NIAID
Innate immune system
Image by US Gov
Macrophage Capturing Foreign Antigen
Cell-mediated immunity is an immune response that does not involve antibodies or complement but rather involves the activation of macrophages, natural killer cells (NK), antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen. Macrophages are white blood cells that engulf and digest cellular debris and pathogens
Image by TheVisualMD
Mast Cell
Mast cells produce histamine. Histamine is known for its role in inflammation. It affects a variety of behavior patterns including the sleep-wake cycle and food intake. Antihistamines may work at odds with inflammation and depression.
Image by TheVisualMD
Leukocytes
Image by OpenStax College
Innate immune system
Illustration of the Innate Immune System responding to injury.
Image by OpenStax College
Eosinophilia
Drawing of an eosinophil white blood cell
Image by Iceclanl
Two neutrophils among many red blood cells. Neutrophils are one type of cell affected by chronic granulomatous disease.
Image by Uploaded by Mgiganteus
Eosinophils
Eosinophil function, relationship to disease, and location in the human body.
Image by NIAID
Sensitive content
This media may include sensitive content
Blood Cells
This is a scanning electron microscope image from normal circulating human blood. One can see red blood cells, several white blood cells including lymphocytes, amonocyte, a neutrophil, and many small disc-shaped platelets. Red cells are nonnucleated and contain hemoglobin, an important protein that contains iron and allows the cell to carry oxygen to other parts of the body. They also carry carbon dioxide away from peripheral tissue to the lungs where it can be exhaled. The infection-fighting white blood cells are classified in two main groups: granular and agranular. All blood cells are formed in the bone marrow. There are two types of agranulocytes: lymphocytes, which fight disease by producing antibodies and thus destroying foreign material, and monocytes. Platelets are tiny cells formed in bone marrow and are necessary for blood clotting.
Image by Bruce Wetzel (photographer). Harry Schaefer (photographer), National Cancer Institute
Immune System and Autoimmune Diseases
Normally, an individual's immune system learns to identify and ignore all of the distinctive little structures found on that individual's own cells. Sometimes, however, it will make a mistake and identify its own body as foreign. If that happens, the immune system produces antibodies that attempt to destroy the body's own cells in the same way it would try to destroy a foreign invader.
Image by TheVisualMD
Eosinophils
Drawing of an eosinophil white blood cell
Image by BruceBlaus
Eosinophils
On the left there is a segmented polymorphonuclear neutrophil, on the right and below is one eosinophil leucocyte. For comparison the red blood cell have a diameter of 7-8 micrometers. The picture was taken with a Nikon Eclipse 600 microscope, magnification was 1000x.
Image by Davidcsaba Dr. David Csaba L.
Neutrophil action - Inflammation
Neutrophil granulocyte migrates from the blood vessel to the matrix, secreting proteolytic enzymes, in order to dissolve intercellular connections (for improvement of its mobility) and envelop bacteria through Phagocytosis.
Image by Uwe Thormann/Wikimedia
Neutrophil
Image by BruceBlaus
White Blood Cells
A type of immune cell. Most white blood cells are made in the bone marrow and are found in the blood and lymph tissue. White blood cells help the body fight infections and other diseases. Granulocytes, monocytes, and lymphocytes are white blood cells.
Image by Blausen.com staff (2014). "Medical gallery of Blausen Medical 2014"
high white blood cell count Video
Video by itbestshop/YouTube
What Are White Blood Cells | Health | Biology | FuseSchool
Video by FuseSchool - Global Education/YouTube
Learning to Decode Your Blood Test Results for Chronic Lymphocytic Leukemia (CLL)
Video by CLL Society/YouTube
WellnessFX: White Blood Cells And Differential with Bryan Walsh
Video by WellnessFX/YouTube
White Blood Count
White Blood Count
Image by TheVisualMD
White Blood Cell Count: Bone Marrow
TheVisualMD
White Blood Cells, Bone Marrow
TheVisualMD
2:12
Complete Blood Count, and Baselining Your Health
TheVisualMD
6:49
The Immune System Explained I – Bacteria Infection
Kurzgesagt – In a Nutshell/YouTube
1:47
Immune Response to Bacteria
NIAID/YouTube
14:59
Immunology - Adaptive Immune System
Armando Hasudungan/YouTube
3:02
Immune System - Natural Killer Cell
Kyle Thornthwaite/YouTube
15:02
Your Immune System: Natural Born Killer - Crash Course Biology #32
CrashCourse/YouTube
White Blood Cell and Red Blood Cell
TheVisualMD
White Blood Cell and Red Blood Cell
TheVisualMD
Red Blood Cell and White Blood Cell
TheVisualMD
Sensitive content
This media may include sensitive content
Blood cells (from left to right: erythrocyte, thrombocyte, leukocyte)
Electron Microscopy Facility at The National Cancer Institute at Frederick (NCI-Frederick)
Bone structure
Smart Servier website
Blood Cells
Blausen.com staff (2014). \"Medical gallery of Blausen Medical 2014\"
Phagocytosis - C-reactive protein (CRP) is a substance made by the liver that is released into the bloodstream by inflammation and infection as part of the body's immune response.
TheVisualMD
White blood cells
NIAID
Neutrophil
NIAID
Innate immune system
US Gov
Macrophage Capturing Foreign Antigen
TheVisualMD
Mast Cell
TheVisualMD
Leukocytes
OpenStax College
Innate immune system
OpenStax College
Eosinophilia
Iceclanl
Two neutrophils among many red blood cells. Neutrophils are one type of cell affected by chronic granulomatous disease.
Uploaded by Mgiganteus
Eosinophils
NIAID
Sensitive content
This media may include sensitive content
Blood Cells
Bruce Wetzel (photographer). Harry Schaefer (photographer), National Cancer Institute
Immune System and Autoimmune Diseases
TheVisualMD
Eosinophils
BruceBlaus
Eosinophils
Davidcsaba Dr. David Csaba L.
Neutrophil action - Inflammation
Uwe Thormann/Wikimedia
Neutrophil
BruceBlaus
White Blood Cells
Blausen.com staff (2014). "Medical gallery of Blausen Medical 2014"
8:22
high white blood cell count Video
itbestshop/YouTube
3:12
What Are White Blood Cells | Health | Biology | FuseSchool
FuseSchool - Global Education/YouTube
1:17:17
Learning to Decode Your Blood Test Results for Chronic Lymphocytic Leukemia (CLL)
CLL Society/YouTube
16:52
WellnessFX: White Blood Cells And Differential with Bryan Walsh
WellnessFX/YouTube
White Blood Count
TheVisualMD
White Blood Cells in Stool Test
White Blood Cells in Stool Test
Also called: Stool for White Cells, Leukocytes in Stool, Fecal Leukocyte Stain, Stool WBC, Fecal WBC, Fecal Leukocyte Test, FLT, Fecal Leukoctye Gram Stain Screen, FGST
A white blood cell in stool (poop) test looks for white blood cells (leukocytes) in stool. The test is used to find out whether diarrhea is caused by conditions that involve inflammation in the digestive system.
White Blood Cells in Stool Test
Also called: Stool for White Cells, Leukocytes in Stool, Fecal Leukocyte Stain, Stool WBC, Fecal WBC, Fecal Leukocyte Test, FLT, Fecal Leukoctye Gram Stain Screen, FGST
A white blood cell in stool (poop) test looks for white blood cells (leukocytes) in stool. The test is used to find out whether diarrhea is caused by conditions that involve inflammation in the digestive system.
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Use the slider below to see how your results affect your
health.
Your result is Negative.
A negative result means no white blood cells (leukocytes) were found in the sample. If you or your child's results were negative, the symptoms are probably not caused by an infection.
Related conditions
This test looks for white blood cells in a sample of your stool (poop). White blood cells are also called leukocytes, so this test is sometimes called a leukocytes in stool test.
White blood cells are part of your immune system. They help your body fight off infections and other diseases. White blood cells in your stool are usually a sign that you have an infection or other condition in your digestive system that's causing inflammation.
A white blood cell in stool test is used if you have diarrhea that could be caused by inflammation. Diarrhea from inflammation is severe and lasts for more than a couple days. It can include blood in stool, abdominal (belly) pain, and fever. It may be caused by:
Certain bacterial infections, such as:
Clostridium difficile (C. diff). This infection mostly happens after taking antibiotics that kill the "good germs" that keep C. diff bacteria from growing in your body.
Some types of bacteria that cause "food poisoning," including:
Salmonella. Most infections come from contaminated food, but you can get salmonella from infected animals, especially reptiles and birds.
Shigella. Infection with shigella is called shigellosis. You can get it from food and touching contaminated surfaces and then touching your mouth.
Campylobacter. Infection can happen from food and contact with dog and cat feces (poop).
Inflammatory bowel disease (IBD), which includes:
Ulcerative colitis
Crohn's disease
A parasite(Entamoeba histolytica) which causes a disease called "amebiasis." Amebiasis is most common in tropical places with poor sanitary conditions.
A white blood cell in stool test can't diagnose the exact condition that's causing diarrhea. But it can help narrow down the possible causes to conditions that either do or don't involve inflammation.
A white blood cell in stool test is used to find out whether diarrhea is caused by conditions that involve inflammation in the digestive system.
It's mainly used for people who have diarrhea symptoms that suggest inflammation. These symptoms include:
Watery diarrhea three or more times a day that doesn't get better after several days
Abdominal (belly) cramps and/or pain
Blood and/or mucus in stool
Fever
Fatigue
Weight loss
A white blood cell in stool test can't diagnose the condition that's causing diarrhea, so it's often used with other tests.
Most diarrhea goes away on its own after a day or two, and your health care provider doesn't need to find the cause. But you may need a white blood cell in stool test and other tests if you have symptoms of diarrhea from inflammation that don't improve after a few days.
Knowing the cause of your diarrhea helps your provider choose the right treatment. That's important because ongoing diarrhea can lead to serious health problems, including dehydration and electrolyte imbalances.
See your provider right away if you have:
Signs of dehydration, including dry mouth, dark urine (pee), fatigue, or dizziness
Diarrhea for more than 2 days, or for more than 24 hours in a young child or infant
A fever of 102 degrees or higher
Severe pain in the abdomen (belly) or rectum
Stool that is black and tarry or contains blood or pus
In adults: frequent vomiting or diarrhea 6 or more times in 24 hours
You will need to provide a stool sample for your test. Your provider will probably give you a container or kit with instructions on how to collect the sample. There are different ways to collect stool samples, so follow the instructions carefully. In general, you'll need to:
Label the container with your name, the collection date, and time.
Collect a stool sample as instructed. This usually involves using a clean, dry container, or special paper or plastic wrap placed over the toilet to catch the stool.
Make sure the stool doesn't mix with any urine, toilet paper, or water from the toilet.
Close the container tightly.
Wash your hands well with soap and water.
Return the container according to the instructions.
If you're collecting a sample from diapers, you'll get special instructions for using plastic wrap inside of a clean diaper. In certain cases, a provider may use a swab to take a stool sample from the rectum.
Certain medicines and foods may affect the test results. Ask your provider if there are any specific things you need to avoid before the test.
There is no known risk to having a white blood cell in stool test.
A positive or abnormal test result means that white blood cells were found in your stool sample. That means you have inflammation in your digestive tract. This information helps rule out conditions that don't cause inflammation, including viral infections, certain bacteria, and most parasites. Other tests can help find out what is causing your illness.
A negative or normal test result means that no white blood cells were found in your stool sample. That may mean that inflammation isn't causing your illness. But a normal test result can't rule out conditions that cause inflammation. That's because white blood cells don't last long in a stool sample.
If your stool sample contained a small number of cells that broke apart during testing, they may not show up. So, you could have inflammation in your digestive system even though your test didn't find any white blood cells in your stool.
Instead of a white blood cell in stool test, your provider may order a more accurate test to check for inflammation in your digestive system. It's called a calprotectin fecal test. Calprotectin is a protein that certain white blood cells release in the intestine when there is inflammation.
White Blood Cell (WBC) in Stool: MedlinePlus Medical Test [accessed on Mar 09, 2023]
https://www.labcorp.com/test-menu/36941/white-blood-cells-wbc-stool [accessed on Apr 05, 2019]
Normal reference ranges can vary depending on the laboratory and the method used for testing. You must use the range supplied by the laboratory that performed your test to evaluate whether your results are "within normal limits."
Platelets
Platelet rotation
Image by TheVisualMD
Platelet rotation
Platelets (also known as thrombocytes - from the Greek for "clotting cell") are actually not full-fledged cells. They are produced by the fragmentation of giant bone marrow cells called megakaryocytes. Platelets contain proteins on their surface that allow them to clump together and adhere to damaged blood vessel walls at the site of injury (they can change their shape to facilitate this process). Platelets also secrete substances that help trigger the series of steps (called the coagulation cascade) necessary for effective clotting.
Image by TheVisualMD
Platelets
You may occasionally see platelets referred to as thrombocytes, but because this name suggests they are a type of cell, it is not accurate. A platelet is not a cell but rather a fragment of the cytoplasm of a cell called a megakaryocyte that is surrounded by a plasma membrane. Megakaryocytes are descended from myeloid stem cells (see image) and are large, typically 50–100 µm in diameter, and contain an enlarged, lobed nucleus. As noted earlier, thrombopoietin, a glycoprotein secreted by the kidneys and liver, stimulates the proliferation of megakaryoblasts, which mature into megakaryocytes. These remain within bone marrow tissue (image) and ultimately form platelet-precursor extensions that extend through the walls of bone marrow capillaries to release into the circulation thousands of cytoplasmic fragments, each enclosed by a bit of plasma membrane. These enclosed fragments are platelets. Each megakarocyte releases 2000–3000 platelets during its lifespan. Following platelet release, megakaryocyte remnants, which are little more than a cell nucleus, are consumed by macrophages.
Platelets are relatively small, 2–4 µm in diameter, but numerous, with typically 150,000–160,000 per µL of blood. After entering the circulation, approximately one-third migrate to the spleen for storage for later release in response to any rupture in a blood vessel. They then become activated to perform their primary function, which is to limit blood loss. Platelets remain only about 10 days, then are phagocytized by macrophages.
Platelets are critical to hemostasis, the stoppage of blood flow following damage to a vessel. They also secrete a variety of growth factors essential for growth and repair of tissue, particularly connective tissue. Infusions of concentrated platelets are now being used in some therapies to stimulate healing.
Source: CNX OpenStax
Additional Materials (17)
Platelets & Blood Clotting | Biology | FuseSchool
Video by FuseSchool - Global Education/YouTube
Decode Your Blood Test: Platelets 💉 | Merck Manual Consumer Version
Video by Merck Manuals/YouTube
Platelets Explained in Two Minutes
Video by American Red Cross/YouTube
The life and times of RBCs and platelets
Video by khanacademymedicine/YouTube
Platelets (Thrombocytes) | The Cell Pieces That Lack Nucleus
Video by Medicosis Perfectionalis/YouTube
Components of the Blood
(a) Platelets are formed from large cells called megakaryocytes. The megakaryocyte breaks up into thousands of fragments that become platelets. (b) Platelets are required for clotting of the blood. The platelets collect at a wound site in conjunction with other clotting factors, such as fibrinogen, to form a fibrin clot that prevents blood loss and allows the wound to heal.
Image by CNX Openstax
Platelets release in mature megakaryocytes
Example of platelets release in mature megakaryocytes. In this footage, we can observe the formation and spontaneous release of platelets (small round-shaped blood cells).
Image by Evilonan
Platelets
Diagram of the internal structure of a human blood platelet
Image by BruceBlaus
Platelet Development
Illustration of Platelet Development
Image by OpenStax College
Platelet Response Animation
The ligands, denoted by letter L, signal for platelets (P) to migrate towards the wound (Site A). As more platelets gather around the opening, they produce more ligands to amplify the response. The platelets congregate around the wound in order to create a cap to stop blood flow out of the tissue.
Image by Bbowen23
Hematopoiesis
Diagram showing the development of different blood cells from haematopoietic stem cell to mature cells
Image by A. Rad
Cell line plasma cells
Diagram showing the cell line plasma cells
Image by Cancer Research UK uploader
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Blood cells (from left to right: erythrocyte, thrombocyte, leukocyte)
A single drop of blood contains millions of red blood cells, white blood cells, and platelets. One of each type is shown here, isolated from a scanning electron micrograph.
Image by Electron Microscopy Facility at The National Cancer Institute at Frederick (NCI-Frederick)
Thrombocytopenia
Thrombocytopenia is a condition where the blood does not contain enough platelets to help it clot efficiently. This can result in a wound that does not heal properly. Thrombocytopenia may be caused by the bone marrow not making enough platelets. Treatment options may include platelet transfusions.
Image by Genetic and Rare Diseases (GARD) Information Center
Blood Donation
The Blood Donor Team stationed at Portsmouth Naval Hospital visits multiple commands throughout the area in efforts to boost the blood supply for the U.S. Armed Forces around the world.
Image by U.S. Navy photo by Photographer's Mate 3rd Class Jeremy L. Grisham
Platelets: Blood Cells
In addition to platelets, there are more than a dozen different blood-clotting factors that interact in the process of blood clotting; even the absence or malfunction of just one of these factors, such as in hemophilia, can disrupt this process and lead to serious illness.
Image by TheVisualMD
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Blood Cells
This is a scanning electron microscope image from normal circulating human blood. One can see red blood cells, several white blood cells including lymphocytes, amonocyte, a neutrophil, and many small disc-shaped platelets. Red cells are nonnucleated and contain hemoglobin, an important protein that contains iron and allows the cell to carry oxygen to other parts of the body. They also carry carbon dioxide away from peripheral tissue to the lungs where it can be exhaled. The infection-fighting white blood cells are classified in two main groups: granular and agranular. All blood cells are formed in the bone marrow. There are two types of agranulocytes: lymphocytes, which fight disease by producing antibodies and thus destroying foreign material, and monocytes. Platelets are tiny cells formed in bone marrow and are necessary for blood clotting.
Image by Bruce Wetzel (photographer). Harry Schaefer (photographer), National Cancer Institute
3:10
Platelets & Blood Clotting | Biology | FuseSchool
FuseSchool - Global Education/YouTube
0:48
Decode Your Blood Test: Platelets 💉 | Merck Manual Consumer Version
Merck Manuals/YouTube
1:47
Platelets Explained in Two Minutes
American Red Cross/YouTube
10:35
The life and times of RBCs and platelets
khanacademymedicine/YouTube
11:39
Platelets (Thrombocytes) | The Cell Pieces That Lack Nucleus
Medicosis Perfectionalis/YouTube
Components of the Blood
CNX Openstax
Platelets release in mature megakaryocytes
Evilonan
Platelets
BruceBlaus
Platelet Development
OpenStax College
Platelet Response Animation
Bbowen23
Hematopoiesis
A. Rad
Cell line plasma cells
Cancer Research UK uploader
Sensitive content
This media may include sensitive content
Blood cells (from left to right: erythrocyte, thrombocyte, leukocyte)
Electron Microscopy Facility at The National Cancer Institute at Frederick (NCI-Frederick)
Thrombocytopenia
Genetic and Rare Diseases (GARD) Information Center
Blood Donation
U.S. Navy photo by Photographer's Mate 3rd Class Jeremy L. Grisham
Platelets: Blood Cells
TheVisualMD
Sensitive content
This media may include sensitive content
Blood Cells
Bruce Wetzel (photographer). Harry Schaefer (photographer), National Cancer Institute
A platelet count test measures the number of platelets in your blood. Platelets, also known as thrombocytes, are small blood cells that are essential for blood clotting. Platelets may be counted to monitor or diagnose diseases, or to look for the cause of too much bleeding or clotting.
A platelet count test measures the number of platelets in your blood. Platelets, also known as thrombocytes, are small blood cells that are essential for blood clotting. Platelets may be counted to monitor or diagnose diseases, or to look for the cause of too much bleeding or clotting.
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Use the slider below to see how your results affect your
health.
(10³)/μL
50
150
450
Your result is Very low.
A lower-than-normal platelet count is called thrombocytopenia. This condition can cause you to bleed too much after a cut or other injury that causes bleeding. If your platelet count is very low, your risk for bleeding is higher. Even every day activities can cause bleeding. Thrombocytopenia can be life-threatening, especially if you have serious bleeding or bleeding in your brain.
Related conditions
Platelets, also known as thrombocytes, are small blood cells that are essential for blood clotting. Clotting is the process that helps you stop bleeding after an injury. There are two types of platelet tests: a platelet count test and platelet function tests.
A platelet count test measures the number of platelets in your blood. A lower than normal platelet count is called thrombocytopenia. This condition can cause you to bleed too much after a cut or other injury that causes bleeding. A higher than normal platelet count is called thrombocytosis. This can make your blood clot more than you need it to. Blood clots can be dangerous because they can block blood flow.
Other names: platelet count, thrombocyte count
A platelet count is most often used to monitor or diagnose conditions that cause too much bleeding or too much clotting. A platelet count may be included in a complete blood count, a test that is often done as part of a regular checkup.
You may need platelet count testing if you have symptoms of having too few or too many platelets.
Symptoms of too few platelets include:
Prolonged bleeding after a minor cut or injury
Nosebleeds
Unexplained bruising
Pinpoint sized red spots on the skin, known as petechiae
Purplish spots on the skin, known as purpura. These may be caused by bleeding under the skin.
Heavy and/or prolonged menstrual periods
Symptoms of too many platelets include:
Numbness of hands and feet
Headache
Dizziness
Weakness
Most platelet tests are done on a blood sample.
During the test, a health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
You don't need any special preparations for a platelet count test.
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
If your results show a lower than normal platelet count (thrombocytopenia), it may indicate:
A cancer that affects the blood, such as leukemia or lymphoma
A viral infection, such as mononucleosis, hepatitis, or measles
An autoimmune disease. This is a disorder that causes the body to attack its own healthy tissues, which can include platelets.
Infection or damage to the bone marrow
Cirrhosis
Vitamin B12 deficiency
Gestational thrombocytopenia, a common, but mild, low-platelet condition affecting pregnant women. It is not known to cause any harm to a mother or her unborn baby. It usually gets better on its own during pregnancy or after birth.
If your results show a higher than normal platelet count (thrombocytosis), it may indicate:
Certain types of cancer, such as lung cancer or breast cancer
Anemia
Inflammatory bowel disease
Rheumatoid arthritis
A viral or bacterial infection
Platelet Tests: MedlinePlus Medical Test [accessed on Jan 20, 2024]
Platelet Count (PLT) Blood Test - Testing.com. Dec 19, 2023 [accessed on Jan 20, 2024]
Platelet count: MedlinePlus Medical Encyclopedia [accessed on Jan 20, 2024]
Normal reference ranges can vary depending on the laboratory and the method used for testing. You must use the range supplied by the laboratory that performed your test to evaluate whether your results are "within normal limits."
Additional Materials (8)
Platelet Development
Illustration of Platelet Development
Image by OpenStax College
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Platelet Disorders
From left to right: erythrocyte, thrombocyte, leukocyte
Image by Electron Microscopy Facility at The National Cancer Institute at Frederick (NCI-Frederick)
Scheme of a blood sample after centrifugation
scheme of a blood sample after centrifugation
Image by KnuteKnudsen (talk)
Decode Your Blood Test: Platelets 💉 | Merck Manual Consumer Version
Video by Merck Manuals/YouTube
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Complete Blood Count, and Baselining Your Health
Video Topics : Our lifeblood consists of many components and a complete blood count (CBC) includes measurements of the fundamental elements. The largest categories are red and white blood cells (RBCs and WBCs) and cell fragments called platelets, which play roles in blood clotting. There are 20-30 trillion red blood cells in the body of an adult, each with a lifespan of about 100 days (RBCs contain an iron-containing protein called hemoglobin that enables them to carry oxygen to tissues throughout the body and then return carbon dioxide to the lungs). WBCs are in the front lines in the body's ongoing fight against harmful viruses, bacteria and even fungus; when a pathogen enters the body, WBCs mobilize in a coordinated defense response to eliminate, neutralize or mark the invader for destruction. The liquid portion of blood is called plasma and it carries nutrients, electrolytes, waste products, and hormones.
Video by TheVisualMD
Platelets Nursing Considerations, Normal Range, Nursing Care, Lab Values Nursing
Video by NURSINGcom/YouTube
Platelets Explained in Two Minutes
Video by American Red Cross/YouTube
The life and times of RBCs and platelets
Video by khanacademymedicine/YouTube
Platelet Development
OpenStax College
Sensitive content
This media may include sensitive content
Platelet Disorders
Electron Microscopy Facility at The National Cancer Institute at Frederick (NCI-Frederick)
Scheme of a blood sample after centrifugation
KnuteKnudsen (talk)
0:48
Decode Your Blood Test: Platelets 💉 | Merck Manual Consumer Version
Merck Manuals/YouTube
2:12
Complete Blood Count, and Baselining Your Health
TheVisualMD
3:54
Platelets Nursing Considerations, Normal Range, Nursing Care, Lab Values Nursing
NURSINGcom/YouTube
1:47
Platelets Explained in Two Minutes
American Red Cross/YouTube
10:35
The life and times of RBCs and platelets
khanacademymedicine/YouTube
Hemoglobin
Hemoglobin A1C Molecule
Image by TheVisualMD
Hemoglobin A1C Molecule
Hemoglobin is a protein found inside red blood cells that carries oxygen from the lungs to cells throughout the body. Hemoglobin also binds with glucose. Diabetics have too much glucose in the bloodstream and this extra glucose binds (or glycates) with hemoglobin. Glycated hemoglobin usually stays glycated for the life of the red blood cell (about 3 months). Therefore, the percentage of hemoglobin that is glycated (measured as A1C) reflects glucose levels that have affected red blood cells up to 3 months in the past.
Image by TheVisualMD
Hemoglobin
Hemoglobin is a large molecule made up of proteins and iron. It consists of four folded chains of a protein called globin, designated alpha 1 and 2, and beta 1 and 2 (imagea). Each of these globin molecules is bound to a red pigment molecule called heme, which contains an ion of iron (Fe2+) (imageb).
Hemoglobin
Hemoglobin (a) A molecule of hemoglobin contains four globin proteins, each of which is bound to one molecule of the iron-containing pigment heme. (b) A single erythrocyte can contain 300 million hemoglobin molecules, and thus more than 1 billion oxygen molecules.
Each iron ion in the heme can bind to one oxygen molecule; therefore, each hemoglobin molecule can transport four oxygen molecules. An individual erythrocyte may contain about 300 million hemoglobin molecules, and therefore can bind to and transport up to 1.2 billion oxygen molecules (see imageb).
In the lungs, hemoglobin picks up oxygen, which binds to the iron ions, forming oxyhemoglobin. The bright red, oxygenated hemoglobin travels to the body tissues, where it releases some of the oxygen molecules, becoming darker red deoxyhemoglobin, sometimes referred to as reduced hemoglobin. Oxygen release depends on the need for oxygen in the surrounding tissues, so hemoglobin rarely if ever leaves all of its oxygen behind. In the capillaries, carbon dioxide enters the bloodstream. About 76 percent dissolves in the plasma, some of it remaining as dissolved CO2, and the remainder forming bicarbonate ion. About 23–24 percent of it binds to the amino acids in hemoglobin, forming a molecule known as carbaminohemoglobin. From the capillaries, the hemoglobin carries carbon dioxide back to the lungs, where it releases it for exchange of oxygen.
Changes in the levels of RBCs can have significant effects on the body’s ability to effectively deliver oxygen to the tissues. Ineffective hematopoiesis results in insufficient numbers of RBCs and results in one of several forms of anemia. An overproduction of RBCs produces a condition called polycythemia. The primary drawback with polycythemia is not a failure to directly deliver enough oxygen to the tissues, but rather the increased viscosity of the blood, which makes it more difficult for the heart to circulate the blood.
In patients with insufficient hemoglobin, the tissues may not receive sufficient oxygen, resulting in another form of anemia. In determining oxygenation of tissues, the value of greatest interest in healthcare is the percent saturation; that is, the percentage of hemoglobin sites occupied by oxygen in a patient’s blood. Clinically this value is commonly referred to simply as “percent sat.”
Percent saturation is normally monitored using a device known as a pulse oximeter, which is applied to a thin part of the body, typically the tip of the patient’s finger. The device works by sending two different wavelengths of light (one red, the other infrared) through the finger and measuring the light with a photodetector as it exits. Hemoglobin absorbs light differentially depending upon its saturation with oxygen. The machine calibrates the amount of light received by the photodetector against the amount absorbed by the partially oxygenated hemoglobin and presents the data as percent saturation. Normal pulse oximeter readings range from 95–100 percent. Lower percentages reflect hypoxemia, or low blood oxygen. The term hypoxia is more generic and simply refers to low oxygen levels. Oxygen levels are also directly monitored from free oxygen in the plasma typically following an arterial stick. When this method is applied, the amount of oxygen present is expressed in terms of partial pressure of oxygen or simply pO2 and is typically recorded in units of millimeters of mercury, mm Hg.
The kidneys filter about 180 liters (~380 pints) of blood in an average adult each day, or about 20 percent of the total resting volume, and thus serve as ideal sites for receptors that determine oxygen saturation. In response to hypoxemia, less oxygen will exit the vessels supplying the kidney, resulting in hypoxia (low oxygen concentration) in the tissue fluid of the kidney where oxygen concentration is actually monitored. Interstitial fibroblasts within the kidney secrete EPO, thereby increasing erythrocyte production and restoring oxygen levels. In a classic negative-feedback loop, as oxygen saturation rises, EPO secretion falls, and vice versa, thereby maintaining homeostasis. Populations dwelling at high elevations, with inherently lower levels of oxygen in the atmosphere, naturally maintain a hematocrit higher than people living at sea level. Consequently, people traveling to high elevations may experience symptoms of hypoxemia, such as fatigue, headache, and shortness of breath, for a few days after their arrival. In response to the hypoxemia, the kidneys secrete EPO to step up the production of erythrocytes until homeostasis is achieved once again. To avoid the symptoms of hypoxemia, or altitude sickness, mountain climbers typically rest for several days to a week or more at a series of camps situated at increasing elevations to allow EPO levels and, consequently, erythrocyte counts to rise. When climbing the tallest peaks, such as Mt. Everest and K2 in the Himalayas, many mountain climbers rely upon bottled oxygen as they near the summit.
Source: CNX OpenStax
Additional Materials (6)
This browser does not support the video element.
Hemoglobin Within Red Blood Cell (RBC)
A red blood cell rushes toward the camera, the camera enters the cell to focus on all of the hemoglobin molecules within
Video by TheVisualMD
This browser does not support the video element.
Hemoglobin A1c
The hemoglobin A1c test measures the percentage of hemoglobin bound to blood sugar (glucose); the test is used to diagnose type 1 and type 2 diabetes. Because the test results reflect average blood sugar levels over a period of 2-3 months (rather than daily fluctuations), the hemoglobin A1C test is also used to gauge how well patients are managing their diabetes over time.
Video by TheVisualMD
This browser does not support the video element.
RBC Oxygenation
Animation showing blood cells flowing through a capillary with a red blood cell becoming oxygenated as it passes in front of the camera. The red blood cell becomes oxygenated by molecules of oxygen diffusing across the membrane of the blood cell where they bind with the hemoglobin within (not shown)
Video by TheVisualMD
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Basophilic Erythroblast
An animation of the second step in red blood cell maturation. Shown in this scene is a basophilic erythroblast (or basophilic normablast) . In this stage cell division ceases, the cell size decreases, and the oxygen binding molecule, hemoglobin begins synthesis . The cell moves from right to left while becoming less focussed. The cell is a violet color contrasting a pink environment mimicking the colors of a histology stained in hematoxylin and eosin (or H&E stain).
Video by TheVisualMD
This browser does not support the video element.
Complete Blood Count, and Baselining Your Health
Video Topics : Our lifeblood consists of many components and a complete blood count (CBC) includes measurements of the fundamental elements. The largest categories are red and white blood cells (RBCs and WBCs) and cell fragments called platelets, which play roles in blood clotting. There are 20-30 trillion red blood cells in the body of an adult, each with a lifespan of about 100 days (RBCs contain an iron-containing protein called hemoglobin that enables them to carry oxygen to tissues throughout the body and then return carbon dioxide to the lungs). WBCs are in the front lines in the body's ongoing fight against harmful viruses, bacteria and even fungus; when a pathogen enters the body, WBCs mobilize in a coordinated defense response to eliminate, neutralize or mark the invader for destruction. The liquid portion of blood is called plasma and it carries nutrients, electrolytes, waste products, and hormones.
Video by TheVisualMD
Hemoglobin A1C molecule
Hemoglobin is a protein found inside red blood cells that carries oxygen from the lungs to cells throughout the body. Hemoglobin also binds with glucose. Diabetics have too much glucose in the bloodstream and this extra glucose binds (or glycates) with hemoglobin. Glycated hemoglobin usually stays glycated for the life of the red blood cell (about 3 months). Therefore, the percentage of hemoglobin that is glycated (measured as A1C) reflects glucose levels that have affected red blood cells up to 3 months in the past.
Image by TheVisualMD
0:27
Hemoglobin Within Red Blood Cell (RBC)
TheVisualMD
0:27
Hemoglobin A1c
TheVisualMD
0:09
RBC Oxygenation
TheVisualMD
0:20
Basophilic Erythroblast
TheVisualMD
2:12
Complete Blood Count, and Baselining Your Health
TheVisualMD
Hemoglobin A1C molecule
TheVisualMD
Hemoglobin Blood Test
Hemoglobin Blood Test
Also called: Hemoglobin, Hgb
A hemoglobin test measures the levels of hemoglobin in your blood. Hemoglobin is an iron-rich protein in red blood cells that carries oxygen. Abnormal levels may mean you have anemia or another blood disorder.
Hemoglobin Blood Test
Also called: Hemoglobin, Hgb
A hemoglobin test measures the levels of hemoglobin in your blood. Hemoglobin is an iron-rich protein in red blood cells that carries oxygen. Abnormal levels may mean you have anemia or another blood disorder.
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Use the slider below to see how your results affect your
health.
g/dL
13.8
17.2
Your result is Low.
Low levels of hemoglobin indicate that there is a shortage of red blood cells; this can be the result of RBCs being lost or destroyed too quickly or produced too slowly.
Related conditions
A hemoglobin test measures the levels of hemoglobin in your blood. Hemoglobin is a protein in your red blood cells that carries oxygen from your lungs to the rest of your body. If your hemoglobin levels are abnormal, it may be a sign that you have a blood disorder.
Other names: Hb, Hgb
A hemoglobin test is often used to check for anemia, a condition in which your body has fewer red blood cells than normal. If you have anemia, the cells in your body don't get all the oxygen they need. Hemoglobin tests are measured as part of a complete blood count (CBC).
Your health care provider may order the test as part of a routine exam, or if you have:
Symptoms of anemia, which include weakness, dizziness, and cold hands and feet
A family history of thalassemia, sickle cell anemia, or other inherited blood disorder
A diet low in iron and other minerals
A long-term infection
Excessive blood loss from an injury or surgical procedure
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
You don't need any special preparation for a hemoglobin test. If your health care provider has ordered other tests on your blood sample, you may need to fast (not eat or drink) for several hours before the test. Your health care provider will let you know if there are any special instructions to follow.
There is very little risk to having a blood test. After the test, some people experience mild pain, dizziness, or bruising. These symptoms usually go away quickly.
There are many reasons your hemoglobin levels may not be in the normal range.
Low hemoglobin levels may be a sign of:
Different types of anemia
Thalassemia
Iron deficiency
Liver disease
Cancer and other diseases
High hemoglobin levels may be a sign of:
Lung disease
Heart disease
Polycythemia vera, a disorder in which your body makes too many red blood cells. It can cause headaches, fatigue, and shortness of breath.
If any of your levels are abnormal, it doesn't always mean you have a medical condition that needs treatment. Diet, activity level, medicines, a menstrual period, and other factors can affect the results. You may also have higher than normal hemoglobin levels if you live in a high altitude area. Talk with your provider to learn what your results mean.
Some forms of anemia are mild, while other types of anemia can be serious and even life threatening if not treated. If you are diagnosed with anemia, be sure to talk to your health care provider to find out the best treatment plan for you.
Hemoglobin Test: MedlinePlus Medical Test [accessed on Jan 20, 2024]
Hemoglobin: MedlinePlus Medical Encyclopedia [accessed on Jan 20, 2024]
Hemoglobin - Health Encyclopedia - University of Rochester Medical Center [accessed on Jan 20, 2024]
Normal reference ranges can vary depending on the laboratory and the method used for testing. You must use the range supplied by the laboratory that performed your test to evaluate whether your results are "within normal limits."
Additional Materials (16)
Hemoglobin | Human anatomy and physiology | Health & Medicine | Khan Academy
Video by Khan Academy/YouTube
Blood, Part 2 - There Will Be Blood: Crash Course A&P #30
Video by CrashCourse/YouTube
Haemoglobin
Video by Wellcome Trust/YouTube
Hemoglobin A1c & Diabetes
Video by DiabeTV/YouTube
Hemoglobin Molecule
Molecule of hemoglobin.
Image by TheVisualMD
Hemoglobin A1C Molecule
Hemoglobin is a protein found inside red blood cells that carries oxygen from the lungs to cells throughout the body. Hemoglobin also binds with glucose. Diabetics have too much glucose in the bloodstream and this extra glucose binds (or glycates) with hemoglobin. Glycated hemoglobin usually stays glycated for the life of the red blood cell (about 3 months). Therefore, the percentage of hemoglobin that is glycated (measured as A1C) reflects glucose levels that have affected red blood cells up to 3 months in the past. The hemoglobin A1C test measures the percentage of hemoglobin bound to blood sugar (glucose); the test is used to diagnose type 1 and type 2 diabetes. Because the test results reflect average blood sugar levels over a period of 2-3 months (rather than daily fluctuations), the hemoglobin A1C test is also used to gauge how well patients are managing their diabetes over time.
Image by TheVisualMD
Hemoglobin A1C: Red Blood Cells
Red blood cells use the iron-rich protein hemoglobin to carry oxygen from the lungs to cells throughout the body and return carbon dioxide to the lungs. The percentage of hemoglobin bound to blood glucose (hemoglobin A1C) is used to diagnose diabetes.
Image by TheVisualMD
Hemoglobin of Red Blood Cell
Hemoglobin is an iron-containing protein found in red blood cells that binds oxygen and carbon dioxide for transport and delivery to different parts of the body.
Image by TheVisualMD
Hemoglobin Molecule
Hemoglobin is an iron-rich protein that is packed inside RBCs. It is a structurally complex molecule that can change shape to either hold or release oxygen, depending on the body's need. There are close to 300 million hemoglobin molecules within each RBC.
Image by TheVisualMD
Hemoglobin Molecule Heme Group
A heme group in a hemoglobin molecule consists of an iron atom bound equally to four nitrogen atoms, all lying in one plane. The iron atom is the site of oxygen binding.
Image by TheVisualMD
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Hemoglobin Within Red Blood Cell (RBC)
A red blood cell rushes toward the camera, the camera enters the cell to focus on all of the hemoglobin molecules within
Video by TheVisualMD
Hemoglobin, Carbon Monoxide
Hemoglobin is an iron-containing protein that enables red blood cells to deliver oxygen from the lungs to cells throughout the body. But the same binding site on the hemoglobin molecule has an even stronger affinity for carbon monoxide, which is why we are so susceptible to poisoning by this deadly gas; carbon monoxide grabs all the binding sites and starves the body's tissues of oxygen
Image by TheVisualMD
This browser does not support the video element.
Hemoglobin A1c
The hemoglobin A1c test measures the percentage of hemoglobin bound to blood sugar (glucose); the test is used to diagnose type 1 and type 2 diabetes. Because the test results reflect average blood sugar levels over a period of 2-3 months (rather than daily fluctuations), the hemoglobin A1C test is also used to gauge how well patients are managing their diabetes over time.
Video by TheVisualMD
Hemoglobin A1c
The hemoglobin A1c test measures the percentage of hemoglobin bound to blood sugar (glucose); the test is used to diagnose type 1 and type 2 diabetes. Because the test results reflect average blood sugar levels over a period of 2-3 months (rather than daily fluctuations), the hemoglobin A1C test is also used to gauge how well patients are managing their diabetes over time.
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Hemoglobin: O2 Binding Hemoglobin
Hemoglobin normally binds to life-sustaining oxygen. But the same binding site on the hemoglobin molecule has an even stronger affinity for carbon monoxide, which is why we are so susceptible to poisoning by this deadly gas.
Image by TheVisualMD
HemoglobinA1C
Hemoglobin Test for O2 Binding Hemoglobin : A hemoglobin test is a measurement of your blood's oxygen-carrying capacity. High levels of hemoglobin can be the result of dehydration, lung disease and other conditions. Low levels of hemoglobin indicate that there is a shortage of red blood cells; this can be the result of RBCs being lost or destroyed too quickly or produced too slowly. Hemoglobin is an iron-containing protein that enables red blood cells to deliver oxygen from the lungs to cells throughout the body. But the same binding site on the hemoglobin molecule has an even stronger affinity for carbon monoxide, which is why we are so susceptible to poisoning by this deadly gas; carbon monoxide grabs all the binding sites and starves the body's tissues of oxygen.
Image by TheVisualMD
14:34
Hemoglobin | Human anatomy and physiology | Health & Medicine | Khan Academy
Khan Academy/YouTube
10:01
Blood, Part 2 - There Will Be Blood: Crash Course A&P #30
CrashCourse/YouTube
5:31
Haemoglobin
Wellcome Trust/YouTube
1:43
Hemoglobin A1c & Diabetes
DiabeTV/YouTube
Hemoglobin Molecule
TheVisualMD
Hemoglobin A1C Molecule
TheVisualMD
Hemoglobin A1C: Red Blood Cells
TheVisualMD
Hemoglobin of Red Blood Cell
TheVisualMD
Hemoglobin Molecule
TheVisualMD
Hemoglobin Molecule Heme Group
TheVisualMD
0:27
Hemoglobin Within Red Blood Cell (RBC)
TheVisualMD
Hemoglobin, Carbon Monoxide
TheVisualMD
0:27
Hemoglobin A1c
TheVisualMD
Hemoglobin A1c
TheVisualMD
Hemoglobin: O2 Binding Hemoglobin
TheVisualMD
HemoglobinA1C
TheVisualMD
Erythrocytes
A computer graphics depiction of a human red blood cell on a glass surface.
Image by Rogeriopfm
A computer graphics depiction of a human red blood cell on a glass surface.
A computer graphics depiction of a human red blood cell on a glass surface.
Image by Rogeriopfm
Erythrocytes
The erythrocyte , commonly known as a red blood cell (or RBC), is by far the most common formed element: A single drop of blood contains millions of erythrocytes and just thousands of leukocytes. Specifically, males have about 5.4 million erythrocytes per microliter (µL) of blood, and females have approximately 4.8 million per µL. In fact, erythrocytes are estimated to make up about 25 percent of the total cells in the body. As you can imagine, they are quite small cells, with a mean diameter of only about 7–8 micrometers (µm) (image). The primary functions of erythrocytes are to pick up inhaled oxygen from the lungs and transport it to the body’s tissues, and to pick up some (about 24 percent) carbon dioxide waste at the tissues and transport it to the lungs for exhalation. Erythrocytes remain within the vascular network. Although leukocytes typically leave the blood vessels to perform their defensive functions, movement of erythrocytes from the blood vessels is abnormal.
Summary of Formed Elements in Blood
Summary of Formed Elements in Blood
The most abundant formed elements in blood, erythrocytes are red, biconcave disks packed with an oxygen-carrying compound called hemoglobin. The hemoglobin molecule contains four globin proteins bound to a pigment molecule called heme, which contains an ion of iron. In the bloodstream, iron picks up oxygen in the lungs and drops it off in the tissues; the amino acids in hemoglobin then transport carbon dioxide from the tissues back to the lungs. Erythrocytes live only 120 days on average, and thus must be continually replaced. Worn-out erythrocytes are phagocytized by macrophages and their hemoglobin is broken down. The breakdown products are recycled or removed as wastes: Globin is broken down into amino acids for synthesis of new proteins; iron is stored in the liver or spleen or used by the bone marrow for production of new erythrocytes; and the remnants of heme are converted into bilirubin, or other waste products that are taken up by the liver and excreted in the bile or removed by the kidneys. Anemia is a deficiency of RBCs or hemoglobin, whereas polycythemia is an excess of RBCs.
Source: CNX OpenStax
Additional Materials (6)
What are Erythrocytes? (Red Blood Cells)
Video by healthery/YouTube
Blood, Part 1 - True Blood: Crash Course A&P #29
Video by CrashCourse/YouTube
Haematology - Red Blood Cells
Video by Armando Hasudungan/YouTube
Red Blood Cell Life Cycle and Disorders, Animation
Video by Alila Medical Media/YouTube
What Are the Components of Blood?
Video by Seeker/YouTube
White and Red Blood Cells
White and Red Blood Cells
Image by TheVisualMD
2:18
What are Erythrocytes? (Red Blood Cells)
healthery/YouTube
10:00
Blood, Part 1 - True Blood: Crash Course A&P #29
CrashCourse/YouTube
9:29
Haematology - Red Blood Cells
Armando Hasudungan/YouTube
4:25
Red Blood Cell Life Cycle and Disorders, Animation
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Blood Count Tests
Your blood contains red blood cells (RBC), white blood cells (WBC), and platelets. Blood count tests measure the number and types of cells in your blood. Blood count tests help doctors check for certain diseases and conditions. Learn about blood count tests, like the complete blood count (CBC).