The thyroid is a gland in your neck that makes thyroid hormones. Thyroid hormones control the rate of many activities in your body, like how fast you burn calories and how fast your heart beats. Thyroid tests check how well your thyroid is working. Read about blood and imaging tests that doctors use to diagnose and monitor thyroid diseases.
Endocrine System, Thyroid, Parathyroid, Thymus and Adrenal glands
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Thyroid Tests
Woman With Goiter Due to Hypothyroidism
Image by TheVisualMD
Woman With Goiter Due to Hypothyroidism
The thyroid is a small, butterfly-shaped gland located at the base of the neck that produces two hormones, thyroxine (T4) and triiodothyronine (T3), that help maintain body temperature, heart rate, moods, and metabolism. A goiter is any visible enlargement of the thyroid gland. In the past, goiters were often due to a lack of iodine in the diet (iodized salt has greatly reduced such goiters). Goiters can be present in cases of either hormone overproduction (hyperthyroidism) or underproduction (hypothyroidism).
Image by TheVisualMD
Thyroid Tests
Your thyroid is a butterfly-shaped gland in your neck, just above your collarbone. It is one of your endocrine glands, which make hormones. Thyroid hormones control the rate of many activities in your body. They include how fast you burn calories and how fast your heart beats. Thyroid tests check how well your thyroid is working. They are also used to diagnose and help find the cause of thyroid diseases such as hyperthyroidism and hypothyroidism. Thyroid tests include blood tests and imaging tests.
Blood tests for your thyroid include
TSH - measures thyroid-stimulating hormone. It is the most accurate measure of thyroid activity.
T3 and T4 - measure different thyroid hormones.
TSI - measures thyroid-stimulating immunoglobulin.
Antithyroid antibody test - measures antibodies (markers in the blood).
Imaging tests include CT scans, ultrasound, and nuclear medicine tests. One type of nuclear medicine test is the thyroid scan. It uses small amounts of radioactive material to create a picture of the thyroid, showing its size, shape, and position. It can help find the cause of hyperthyroidism and check for thyroid nodules (lumps in the thyroid). Another nuclear test is the radioactive iodine uptake test, or thyroid uptake test. It checks how well your thyroid is working and can help find the cause of hyperthyroidism.
Source: NIH: National Institute of Diabetes and Digestive and Kidney Diseases
Additional Materials (2)
The Thyroid Exam and Physical Diagnosis of Thyroid Disease
Video by Strong Medicine/YouTube
Thyroid Problems Explained: Symptoms of #Thyroid Conditions and Who Should Get a Thyroid Check
Video by LetsGetChecked/YouTube
20:39
The Thyroid Exam and Physical Diagnosis of Thyroid Disease
Strong Medicine/YouTube
9:21
Thyroid Problems Explained: Symptoms of #Thyroid Conditions and Who Should Get a Thyroid Check
LetsGetChecked/YouTube
What Do They Look For?
Thyroid Gland
Image by TheVisualMD
Thyroid Gland
The thyroid is a small, butterfly-shaped gland located at the base of the neck, just below the Adam`s apple. Hormones produced by the thyroid gland have an enormous impact on many aspects of metabolism.
Image by TheVisualMD
What Do Thyroid Tests Look For?
Health care professionals use thyroid tests to check how well your thyroid is working and to find the cause of problems such as hyperthyroidism or hypothyroidism. The thyroid is a small, butterfly-shaped gland in the front of your neck that makes two thyroid hormones: thyroxine (T4) and triiodothyronine (T3). Thyroid hormones control how the body uses energy, so they affect nearly every organ in your body, even your heart.
The thyroid is a small, butterfly-shaped gland in your neck.
Thyroid tests help health care professionals diagnose thyroid diseases such as
hyperthyroidism—when thyroid hormone levels are too high
Graves’ disease, the most common cause of hyperthyroidism
hypothyroidism—when thyroid hormones levels are too low
Hashimoto’s disease, of the most common cause of hypothyroidism
thyroid nodules and thyroid cancer
Your doctor will start with blood tests and may also order imaging tests.
Source: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Additional Materials (2)
Thyroglobulin Molecule
Thyroglobulin (Tg) is a protein produced by the thyroid, a 2-inch, butterfly-shaped endocrine gland in the base of the neck that helps control metabolism. It's normal for Tg levels in the blood to be low or entirely absent, because the protein is used exclusively by the thyroid to produce the thyroid hormones thyroxine (T4) and triiodothyronine (T3). The two most common types of thyroid cancer, papillary and follicular, cause the thyroid to produce excess thyroglobulin, which can be detected in the blood.
Image by TheVisualMD
Thyroxine-binding Globulin
Thyroxine-binding globulin binds thyroid hormone in circulation. It is one of three proteins (along with transthyretin and albumin) responsible for carrying the thyroid hormones thyroxine (T4) and 3,5,3'-triiodothyronine (T3) in the bloodstream. Of these three proteins, TBG has the highest affinity for T4 and T3, but is present in the lowest concentration. Despite its low concentration, TBG carries the majority of T4 in the blood. Due to the very low concentration of T4 & T3 in the blood, TBG is rarely more than 25% saturated with its ligand. Unlike transthyretin and albumin, TBG has a single binding site for T4/T3. TBG is synthesized primarily in the liver as a 54 kDa protein. In terms of genomics, TBG is a serpin; however, it has no inhibitory function like many other members of this class of proteins.
Image by TheVisualMD
Thyroglobulin Molecule
TheVisualMD
Thyroxine-binding Globulin
TheVisualMD
Blood Tests
Importance of Thyroid Gland
Image by TheVisualMD
Importance of Thyroid Gland
The thyroid and the hormones it produces, for example, are under control of a hormone called TSH (thyroid-stimulating hormone), which is produced by the pituitary gland. The pituitary gland is often referred to as the "master gland" because it regulates the activities of other endocrine glands. The pituitary gland, however, takes its orders from the hypothalamus, which decides which particular hormones the pituitary should release and when.
Image by TheVisualMD
What Blood Tests Do Doctors Use to Check Thyroid Function?
Doctors may order one or more blood tests to check your thyroid function. Tests may include thyroid stimulating hormone (TSH), T4, T3, and thyroid antibody tests.
For these tests, a health care professional will draw blood from your arm and send it to a lab for testing. Your doctor will talk to you about your test results.
TSH test
Health care professionals usually check the amount of TSH in your blood first. TSH is a hormone made in the pituitary gland that tells the thyroid how much T4 and T3 to make.
A high TSH level most often means you have hypothyroidism, or an underactive thyroid. This means that your thyroid isn’t making enough hormone. As a result, the pituitary keeps making and releasing TSH into your blood.
A low TSH level usually means you have hyperthyroidism, or an overactive thyroid. This means that your thyroid is making too much hormone, so the pituitary stops making and releasing TSH into your blood.
If the TSH test results are not normal, you will need at least one other test to help find the cause of the problem.
T4 tests
A high blood level of T4 may mean you have hyperthyroidism. A low level of T4 may mean you have hypothyroidism.
In some cases, high or low T4 levels may not mean you have thyroid problems. If you are pregnant or are taking oral contraceptives, your thyroid hormone levels will be higher. Severe illness or using corticosteroids—medicines to treat asthma, arthritis, skin conditions, and other health problems—can lower T4 levels. These conditions and medicines change the amount of proteins in your blood that “bind,” or attach, to T4. Bound T4 is kept in reserve in the blood until it’s needed. “Free” T4 is not bound to these proteins and is available to enter body tissues. Because changes in binding protein levels don’t affect free T4 levels, many healthcare professionals prefer to measure free T4.
T3 test
If your health care professional thinks you may have hyperthyroidism even though your T4 level is normal, you may have a T3 test to confirm the diagnosis. Sometimes T4 is normal yet T3 is high, so measuring both T4 and T3 levels can be useful in diagnosing hyperthyroidism.
Thyroid antibody tests
Measuring levels of thyroid antibodies may help diagnose an autoimmune thyroid disorder such as Graves’ disease—the most common cause of hyperthyroidism—and Hashimoto’s disease—the most common cause of hypothyroidism. Thyroid antibodies are made when your immune system attacks the thyroid gland by mistake. Your health care professional may order thyroid antibody tests if the results of other blood tests suggest thyroid disease.
Source: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Additional Materials (1)
Thyroid Stimulating Hormone (TSH) Molecule
The TSH test measures the amount of thyroid-stimulating hormone circulating in the bloodstream. Our bodies have a finely tuned feedback system that turns thyroid hormone production on and off. When levels of thyroid hormones are too low, the hypothalamus releases a hormone which causes the pituitary gland to release thyroid-stimulating hormone (TSH), which in turn stimulates the thyroid gland to increase production of thyroid hormones. As levels of thyroid hormones rise, TSH release is inhibited and TSH levels drop.
Image by TheVisualMD
Thyroid Stimulating Hormone (TSH) Molecule
TheVisualMD
TSH Test
TSH (Thyroid-Stimulating Hormone) Test
Also called: TSH, Thyroid-Stimulating Hormone, Thyrotropin
The test measures the amount of thyroid-stimulating hormone (TSH) in a sample of your blood. TSH is made in the pituitary gland and stimulates the release of thyroid hormone. If your TSH levels are too high or too low, it can indicate a thyroid disorder.
TSH (Thyroid-Stimulating Hormone) Test
Also called: TSH, Thyroid-Stimulating Hormone, Thyrotropin
The test measures the amount of thyroid-stimulating hormone (TSH) in a sample of your blood. TSH is made in the pituitary gland and stimulates the release of thyroid hormone. If your TSH levels are too high or too low, it can indicate a thyroid disorder.
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Use the slider below to see how your results affect your
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(mi.U.)/mL
0.45
4.5
Your result is Normal.
The pituitary gland releases TSH into the blood to stimulate the thyroid to make more thyroid hormone. The amount of TSH that the pituitary sends into the bloodstream depends on the amount of thyroid hormone in the body. In most healthy individuals, a normal TSH value means that the thyroid is functioning properly.
Related conditions
TSH stands for thyroid stimulating hormone. A TSH test is a blood test that measures this hormone. TSH levels that are too high or too low may be a sign of a thyroid problem.
The thyroid is a small, butterfly-shaped gland in the front of your neck. Your thyroid makes hormones that control how your body uses energy. Thyroid hormones affect nearly every organ in your body, including your heart. They help control your weight, body temperature, muscle strength, and even your mood. If you don't have enough thyroid hormones in your blood, many of your body functions slow down. If you have too much, many body functions speed up.
Your thyroid is controlled by a gland in your brain, called the pituitary gland. The pituitary gland makes thyroid stimulating hormone (TSH). TSH tells your thyroid how much thyroid hormone it needs to make.
If the thyroid hormone levels in your blood are too low, your pituitary gland makes larger amounts of TSH to tell your thyroid to work harder. If your thyroid hormone levels are too high, the pituitary gland makes little or no TSH. By measuring TSH levels in your blood, you can find out if your thyroid is making the right level of hormones.
Other names: thyrotropin test
A TSH test is used to find out how well your thyroid is working. It can tell if you have hyperthyroidism (too much thyroid hormone) or hypothyroidism (too little thyroid hormone) in your blood. But a TSH test can't show what is causing a thyroid problem.
If you take prescription thyroid hormone medicine because of hypothyroidism or because you had your thyroid removed, you'll have regular TSH tests to check your thyroid hormone levels. TSH tests are also used to monitor your thyroid hormone levels after treatment for hyperthyroidism.
You may need a TSH test if you have symptoms of too much or too little thyroid hormone in your blood.
Hyperthyroidism (too much thyroid hormone) is also called overactive thyroid. Having more thyroid hormones than you need speeds up your body functions and causes symptoms that include:
Weight loss, even though you may be eating more than usual
Rapid or irregular heartbeat
Feeling nervous or irritable
Trouble sleeping, fatigue
Shaky hands, muscle weakness
Sweating or being very sensitive to heat
Frequent bowel movements (pooping a lot)
Goiter (enlarged thyroid)
Hypothyroidism (too little thyroid hormone) is also called underactive thyroid. Not having enough thyroid hormone slows down your body functions and causes symptoms that include:
Fatigue
Weight gain
Being very sensitive to cold
Joint and muscle pain
Dry skin
Dry, thinning hair
Heavy or irregular menstrual periods
Depression
Constipation
You may also have a TSH test, along with other tests, to help diagnose unusual bumps or lumps on your thyroid that may be thyroid cancer or thyroid nodules (growths on your thyroid that aren't cancer).
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 TSH blood test. If your health care provider has ordered other blood tests, 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 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 TSH test results can tell you if your thyroid is making too much or too little thyroid. But the test can't explain why your TSH levels may be too high or too low.
If your test results aren't normal, your provider will probably order other thyroid blood tests to find out what's causing your thyroid problem. These blood tests may include:
T4 thyroid hormone test
T3 thyroid hormone test
Thyroid antibodies test to help diagnose an autoimmune thyroid disorder, such as:
Graves' disease, the most common cause of hyperthyroidism
Hashimoto's disease, that the most common cause of hypothyroidism
In certain cases, an abnormal TSH result may be a sign of a pituitary gland problem, but this doesn't happen often.
TSH levels may be high or low even when your thyroid gland is healthy. Serious illnesses not related to your thyroid may cause lower TSH levels for a short time. And TSH levels may be higher in people over age 80, even though they don't have any thyroid problems.
Pregnancy also affects TSH levels. They are often a little low during the first three months. But sometimes, thyroid disease develops during pregnancy. If you develop thyroid disease during pregnancy, your provider will monitor your condition through your pregnancy and after your baby is born. That's because hyperthyroidism, and less often, hypothyroidism, can continue after you give birth. If you have a history of thyroid disease, be sure to talk with your provider if you are pregnant or are thinking of becoming pregnant.
Newborn babies are routinely screened with a TSH test to see if they were born with hypothyroidism (congenital hypothyroidism).
004259: Thyroid-stimulating Hormone (TSH) | LabCorp [accessed on Oct 04, 2018]
TSH test: MedlinePlus Medical Encyclopedia [accessed on Oct 04, 2018]
TSH [accessed on Oct 04, 2018]
004593: Thyroid-stimulating Hormone (TSH) in Pregnancy | LabCorp [accessed on Oct 04, 2018]
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 (28)
Thyroid Gland
The thyroid is a small, butterfly-shaped gland located at the base of the neck, just below the Adam's apple. The thyroid gland produces two main hormones, thyroxine (T4) and triiodothyronine (T3), which play key roles in regulating many aspects of metabolism, the rate at which the cells use energy and carry out chemical processes. The thyroid and the hormones it produces are under the control of a hormone called TSH (thyroid-stimulating hormone) produced by the pituitary gland.
Image by TheVisualMD
Importance of Thyroid Gland
The thyroid and the hormones it produces, for example, are under control of a hormone called TSH (thyroid-stimulating hormone), which is produced by the pituitary gland. The pituitary gland is often referred to as the "master gland" because it regulates the activities of other endocrine glands. The pituitary gland, however, takes its orders from the hypothalamus, which decides which particular hormones the pituitary should release and when.
Image by TheVisualMD
Thyroid Gland
Image by CFCF
Follicular Cell of Thyroid Gland
The thyroid is a small, butterfly-shaped gland located at the base of the neck, just below the Adam's apple. The thyroid gland produces two main hormones, thyroxine (T4) and triiodothyronine (T3). The hormones help maintain body temperature, heart rate, moods, energy levels, bowel function and rates of fat, protein and carbohydrate metabolism. The thyroid contains spherical follicles that absorb iodine ions from the blood for use in the production of T4 and T3. Iodine deficiency, rare in the U.S., affects two billion people worldwide and is the leading preventable cause of mental retardation.
Image by TheVisualMD
Woman with visible Brain revealing Pituitary Gland
The pituitary gland is a pea-sized endocrine gland located at the base of the skull, between the optic nerves. It is often referred to as the endocrine system's \"master gland\" because it regulates the activities of other glands. The pituitary, however, takes its orders from the hypothalamus, which decides which particular hormones the pituitary should release and when. The pituitary governs testosterone and estrogen production, as well as ovulation and breast milk production; it also helps regulate growth, blood pressure, maintain proper fluid balance, and other aspects of metabolism.
Image by TheVisualMD
Follicle-stimulating hormone
Follicle-stimulating hormone
Image by MartaFF
Follicle-stimulating hormone
The time scale starts with the (LMP), given as day number. Day number 1 corresponds to 0 to 0.99 days from LMP, and Day number 2 corresponds to 1.00 to 1.99 days from LMP and so forth. The time scale ends at whatever is the actual next menstruation, which marks the beginning of the next cycle, which is equivalent to starting all over again from the beginning of the time scale.
Image by Mikael Haggstrom
hCG testing for pregnancy
Diagram of typical immunoassay home pregnancy test which detects human chorionic gonadotropin (hCG). (A) A urine sample is applied to the stick. If pregnant, this should contain hCG. (B) As the sample is absorbed into the stick it goes through free dye-labeled antibodies that recognize and stick to hCG. (C) An anchored set of antibodies stick to and capture hCG molecules (and the attached dye-labeled antibodies), creating the first line. In the "not pregnant" sample no hCG is attached to the dye-labeled antibodies, so they wash past this point and no line appears. (D) A second anchored set of antibodies captures the dye-labeled antibodies, providing a positive control to indicate that the test is working properly.
Image by Madprime
The classic finding of exophthalmos and lid retraction in Graves' disease
Proptosis and Lid Retraction from Graves Disease : Photograph showing a classic finding of Graves' Disease, proptosis and lid retraction.
Image by Jonathan Trobe, M.D. - University of Michigan Kellogg Eye Center
What are the symptoms of Graves' disease?
Graves' disease symptoms
Image by Original uploader was Madhero88 at en.wikipedia
What is Graves' ophthalmopathy?
Magnetic Resonance Imaging of the orbits, showing congestion of the retro-orbital space and enlargement of the extraocular muscles (arrows), consistent with the diagnosis of Graves' Ophthalmopathy.
Image by Huy A Tran and Glenn EM Reeves
Thyroid Gland
The thyroid is a small, butterfly-shaped gland located at the base of the neck, just below the Adam`s apple. Hormones produced by the thyroid gland have an enormous impact on many aspects of metabolism.
Image by TheVisualMD
Thyroid Stimulating Hormone
A Classic Negative Feedback Loop
Image by OpenStax College
Woman's neck region with visible thyroid
The thyroid is a small, butterfly-shaped gland located at the base of the neck. The gland produces two main hormones, thyroxine and triiodothyronine. The hormones help maintain body temperature, heart rate, moods, energy levels, bowel function and rates of fat, protein and carbohydrate metabolism. The thyroid is under the control of a hormone called thyroid-stimulating hormone produced by the pituitary gland; the pituitary gland, in turn, takes its orders from the hypothalamus. Thyroid problems usually fall into one of two categories: hypothroidism, when the gland produces too little hormone; or hyperthroidism, when the gland produces too much.
Image by TheVisualMD
Woman with Visible Thyroid
The thyroid is a small, butterfly-shaped gland located at the base of the neck, just below the Adam's apple. The thyroid gland produces two main hormones, thyroxine (T4) and triiodothyronine (T3). The hormones help maintain body temperature, heart rate, moods, energy levels, bowel function and rates of fat, protein and carbohydrate metabolism. The thyroid and the hormones it produces are under the control of a hormone called TSH (thyroid-stimulating hormone) produced by the pituitary gland, which is often referred to as the \"master gland\" because it regulates the activities of other endocrine glands.
Image by TheVisualMD
Thyroid Stimulating Hormone (TSH)
The thyroid is a small, butterfly-shaped gland located at the base of the neck that produces hormones that help maintain body temperature, heart rate, moods, and metabolism. Hyperthyroidism (when too much hormone is produced) is often caused by an autoimmune disorder called Graves' disease, in which antibodies produced by the immune system over-stimulate the thyroid. The production of thyroid hormones is under the control of a hormone called TSH (thyroid-stimulating hormone) produced by the pituitary gland.
Image by TheVisualMD
Woman With Goiter Due to Hypothyroidism
The thyroid is a small, butterfly-shaped gland located at the base of the neck that produces two hormones, thyroxine (T4) and triiodothyronine (T3), that help maintain body temperature, heart rate, moods, and metabolism. A goiter is any visible enlargement of the thyroid gland. In the past, goiters were often due to a lack of iodine in the diet (iodized salt has greatly reduced such goiters). Goiters can be present in cases of either hormone overproduction (hyperthyroidism) or underproduction (hypothyroidism).
Image by TheVisualMD
Hormonal Control of the Menstrual Cycle, Animation.
Video by Alila Medical Media/YouTube
What Is High FSH?
Video by fertilityauthority/YouTube
What is FSH?
Video by fertilityauthority/YouTube
Human Physiology - Hormonal Regulation of Male Reproduction
Thyroid gland - What's the function of the thyroid?
Video by Healthchanneltv / cherishyourhealthtv/YouTube
Normal Thyroid cell
A normal thyroid cell (Nthy.ori 3-1) adhered to gold surface. Picture taken by a Scanning electron microscope (SEM), University of Crete, Heraklion, Greece.
Image by ChronakiDimitra
Thyroid scintigraphy
5 different scintigramms taken from thyroids with different syndroms: A) normal thyroid, B) Graves disease, diffuse increased uptake in both thyroid lobes, C) Plummers disease (TMNG, toxic multinodular goitre), D) Toxic adenoma, E) Thyroiditis. Marker 99Tc
Image by Petros Perros
Thyroid Gland
TheVisualMD
Importance of Thyroid Gland
TheVisualMD
Thyroid Gland
CFCF
Follicular Cell of Thyroid Gland
TheVisualMD
Woman with visible Brain revealing Pituitary Gland
TheVisualMD
Follicle-stimulating hormone
MartaFF
Follicle-stimulating hormone
Mikael Haggstrom
hCG testing for pregnancy
Madprime
The classic finding of exophthalmos and lid retraction in Graves' disease
Jonathan Trobe, M.D. - University of Michigan Kellogg Eye Center
What are the symptoms of Graves' disease?
Original uploader was Madhero88 at en.wikipedia
What is Graves' ophthalmopathy?
Huy A Tran and Glenn EM Reeves
Thyroid Gland
TheVisualMD
Thyroid Stimulating Hormone
OpenStax College
Woman's neck region with visible thyroid
TheVisualMD
Woman with Visible Thyroid
TheVisualMD
Thyroid Stimulating Hormone (TSH)
TheVisualMD
Woman With Goiter Due to Hypothyroidism
TheVisualMD
3:15
Hormonal Control of the Menstrual Cycle, Animation.
Alila Medical Media/YouTube
1:16
What Is High FSH?
fertilityauthority/YouTube
2:46
What is FSH?
fertilityauthority/YouTube
3:38
Human Physiology - Hormonal Regulation of Male Reproduction
Thyroid gland - What's the function of the thyroid?
Healthchanneltv / cherishyourhealthtv/YouTube
Normal Thyroid cell
ChronakiDimitra
Thyroid scintigraphy
Petros Perros
T3 Test
Thyroxine Test
Also called: Thyroxine Screen, Tetraiodothyronine
This test measures the level of thyroxine (T4) in the blood. T4 is the main hormone secreted into the bloodstream by the thyroid gland. Too much or too little T4 can indicate thyroid disease.
Thyroxine Test
Also called: Thyroxine Screen, Tetraiodothyronine
This test measures the level of thyroxine (T4) in the blood. T4 is the main hormone secreted into the bloodstream by the thyroid gland. Too much or too little T4 can indicate thyroid disease.
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Use the slider below to see how your results affect your
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μg/dL
4.5
12
Your result is Normal.
Normal results vary based on the laboratory and the method used.
Related conditions
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Use the slider below to see how your results affect your
health.
ng/dL
0.82
1.77
Your result is Normal.
Normal results vary based on the laboratory and the method used.
Related conditions
A thyroxine test is a blood test that helps diagnose thyroid conditions. The thyroid is a small, butterfly-shaped gland at the base of your throat. Your thyroid makes hormones that control the way your body uses energy. These hormones affect your weight, heart, body temperature, muscle strength, and even your mood. In children, thyroid hormones affect growth, too.
Thyroxine, also known as T4, is a type of thyroid hormone. A T4 test measures the level of T4 in your blood. Too much or too little T4 can be a sign of thyroid disease.
There are two forms of T4 in your blood:
Free T4 is the active form of thyroxine hormone that enters your tissues where it's needed.
Bound T4 is thyroxine that attaches or binds to certain proteins which prevent it from entering your tissues.
T4 levels can be measured with either a free T4 test or a total T4 test:
A free T4 test directly measures the amount of free T4 in your blood. Medical experts believe this test provides more accurate information than a total T4 test, so it's used more often.
A total T4 test measures free and bound T4 together. A calculation may be done to figure out how much T4 is free. This is a less accurate way to check how well your thyroid is working.
Other names: free thyroxine, free T4, total T4 concentration, T4 index, thyroxine screen, free T4 concentration, thyroxine test by equilibrium dialysis
A T4 test is used to check how well your thyroid is working. It's also used to help diagnose and monitor thyroid disease and conditions that may affect your thyroid, including:
Hypothyroidism, or underactive thyroid, which is when your thyroid gland doesn't make enough thyroid hormone to meet your body's needs
Hyperthyroidism, or overactive thyroid, which is when your thyroid gland makes more thyroid hormone than your body needs
Disorders of the pituitary gland, which is a gland at the base of your brain that makes TSH (thyroid stimulating hormone). TSH controls how much T4 your thyroid gland makes. If the results from a TSH test aren't normal, a T4 test can help diagnose whether the problem is with your thyroid or your pituitary gland.
In certain cases, a T4 test may be done as part of a group of tests called a thyroid panel. A thyroid panel includes a test for TSH as well as other thyroid tests.
You may need a T4 test if your provider thinks you may have a thyroid problem. Usually, a TSH test is done first. If your TSH results aren't normal, a T4 test may be done to learn more.
Thyroid problems tend to run in families, so your provider may order a T4 test if a member of your family has had thyroid disease. You may also need a T4 test if you have symptoms of having too much or too little thyroid hormone.
Symptoms of hypothyroidism (too little thyroid hormone), may include:
Weight gain
Fatigue
Dry skin
Dry, thinning hair
Being very sensitive to cold temperatures
Heavy or irregular menstrual periods or fertility problems
Slow heart rate
Depression
Symptoms of hyperthyroidism (too much thyroid hormone) may include:
Anxiety, nervousness, irritability
Weight loss, even though your appetite may increase
Shaky hands, muscle weakness
Sweating or being very sensitive to heat
Arrhythmia (a problem with the rate or rhythm of your heartbeat)
Frequent bowel movements (poops)
Goiter (an enlarged thyroid gland)
Trouble sleeping and fatigue
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.
In most cases, you don't need any special preparations for a thyroxine blood test. Certain medicines and supplements may affect your test results, so let your provider know what you're taking, but don't stop any medicines without talking with your provider.
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 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. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
If you had a free T4 test, your test results may be reported as "free T4." If you had a total T4 test, your results may be reported as "free T4 index (FTI)." To fully understand your results, your provider will often need to compare them with the results of other thyroid tests.
In general, T4 results that are lower than normal may be a sign of:
Hypothyroidism, which may be caused by Hashimoto disease or another medical condition that causes your thyroid to make too little T4
Thyroiditis (thyroid inflammation)
Side effects from certain drugs
Congenital hypothyroidism (a condition that affects babies from birth)
In general, T4 results that are higher than normal may be a sign of:
Hyperthyroidism, which may be caused by Graves disease or another medical condition that causes your thyroid to make too much T4
Thyroiditis (thyroid inflammation)
Toxic goiter (an enlarged thyroid with areas that make extra thyroid hormone)
Toxic thyroid nodule (a single lump on the thyroid that makes extra thyroid hormone)
Too much iodine in your diet
A noncancerous (not cancer) tumor in your pituitary gland
Talk with your provider about what your results mean.
Thyroid disease can develop during pregnancy, but it's not common. Hyperthyroidism, and less often, hypothyroidism, may remain after pregnancy.
If you develop a thyroid condition during pregnancy, your provider will monitor your condition after your baby is born. Also, if you have a history of thyroid disease, be sure to talk with your provider if you are pregnant or are thinking of becoming pregnant.
Newborn babies usually have a T4 test to screen for congenital hypothyroidism.
Thyroxine (T4) Test: MedlinePlus Lab Test Information [accessed on Oct 03, 2018]
000620: Thyroid Profile With TSH | LabCorp [accessed on Oct 03, 2018]
T4 - Clinical: T4 (Thyroxine), Total Only, Serum [accessed on Oct 03, 2018]
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 (15)
Thyroxine, Total (T4): Thyroid Gland
The thyroid is a 2-inch, butterfly-shaped gland located at the base of the neck, just below the Adam's apple. The gland consists of two lobes, which lie on either side of the windpipe. The thyroid produces the hormones thyroxine (T4) and triiodothyronine (T3), which help maintain body temperature, heart rate, and metabolism rates.
Image by TheVisualMD
Importance of Thyroid Gland
The thyroid and the hormones it produces, for example, are under control of a hormone called TSH (thyroid-stimulating hormone), which is produced by the pituitary gland. The pituitary gland is often referred to as the "master gland" because it regulates the activities of other endocrine glands. The pituitary gland, however, takes its orders from the hypothalamus, which decides which particular hormones the pituitary should release and when.
Image by TheVisualMD
Thyroxine, Total (T4): Pituitary Gland
The pituitary is a pea-size gland attached to the base of the brain. It is often referred to as the \"master gland\" because it regulates the activities of other endocrine glands. The pituitary, however, takes its orders from the hypothalamus, an area of the brain that sits above the pituitary and is connected to it by neurons. The hypothalamus decides which particular hormones the pituitary should release and when.
Image by TheVisualMD
Woman With Goiter Due to Hypothyroidism
The thyroid is a small, butterfly-shaped gland located at the base of the neck that produces two hormones, thyroxine (T4) and triiodothyronine (T3), that help maintain body temperature, heart rate, moods, and metabolism. A goiter is any visible enlargement of the thyroid gland. In the past, goiters were often due to a lack of iodine in the diet (iodized salt has greatly reduced such goiters). Goiters can be present in cases of either hormone overproduction (hyperthyroidism) or underproduction (hypothyroidism).
Image by TheVisualMD
Thyroxine 3D Molecule
The major hormone derived from the thyroid gland. Thyroxine is synthesized via the iodination of tyrosines (MONOIODOTYROSINE) and the coupling of iodotyrosines (DIIODOTYROSINE) in the THYROGLOBULIN. Thyroxine is released from thyroglobulin by proteolysis and secreted into the blood. Thyroxine is peripherally deiodinated to form TRIIODOTHYRONINE which exerts a broad spectrum of stimulatory effects on cell metabolism. (MESH/NLM/NIH)
Thyroid problems - most common thyroid problems, symptoms and treatment
Video by Healthchanneltv / cherishyourhealthtv/YouTube
Thyroid gland - What's the function of the thyroid?
Video by Healthchanneltv / cherishyourhealthtv/YouTube
Thyroid Animation
Video by Columbia University Department of Surgery/YouTube
Thyroid Gland, Hormones and Thyroid Problems, Animation
Video by Alila Medical Media/YouTube
Thyroid Gland - Thyroid Hormones
Video by Armando Hasudungan/YouTube
How does the thyroid manage your metabolism? - Emma Bryce
Video by TED-Ed/YouTube
Understanding Thyroid Function Tests
Video by AdonaiDEC/YouTube
T3 And T4, What Do They Do?
Video by EmpowHER/YouTube
Woman's neck region with visible thyroid
The thyroid is a small, butterfly-shaped gland located at the base of the neck. The gland produces two main hormones, thyroxine and triiodothyronine. The hormones help maintain body temperature, heart rate, moods, energy levels, bowel function and rates of fat, protein and carbohydrate metabolism. The thyroid is under the control of a hormone called thyroid-stimulating hormone produced by the pituitary gland; the pituitary gland, in turn, takes its orders from the hypothalamus. Thyroid problems usually fall into one of two categories: hypothroidism, when the gland produces too little hormone; or hyperthroidism, when the gland produces too much.
Image by TheVisualMD
Thyroxine
The structural formula (left) and a space-filling model (right) of (S)-triiodothyronine (T3, also called liothyronine in the pharmaceutical industry)
Image by Benjah-bmm27
Thyroxine, Total (T4): Thyroid Gland
TheVisualMD
Importance of Thyroid Gland
TheVisualMD
Thyroxine, Total (T4): Pituitary Gland
TheVisualMD
Woman With Goiter Due to Hypothyroidism
TheVisualMD
Thyroxine 3D Molecule
4:11
Thyroid problems - most common thyroid problems, symptoms and treatment
Healthchanneltv / cherishyourhealthtv/YouTube
1:55
Thyroid gland - What's the function of the thyroid?
Healthchanneltv / cherishyourhealthtv/YouTube
1:48
Thyroid Animation
Columbia University Department of Surgery/YouTube
4:03
Thyroid Gland, Hormones and Thyroid Problems, Animation
Alila Medical Media/YouTube
12:47
Thyroid Gland - Thyroid Hormones
Armando Hasudungan/YouTube
3:37
How does the thyroid manage your metabolism? - Emma Bryce
TED-Ed/YouTube
6:07
Understanding Thyroid Function Tests
AdonaiDEC/YouTube
1:56
T3 And T4, What Do They Do?
EmpowHER/YouTube
Woman's neck region with visible thyroid
TheVisualMD
Thyroxine
Benjah-bmm27
T4 Test
Triiodothyronine (T3) Tests
Also called: T3 Test, T3 Free and Total
This test measures triiodothyronine (T3) in your blood. Your thyroid gland makes T3. T3 plays an important role in the body's control of metabolism (the many processes that control the rate of activity in cells and tissues). The test is mainly used to diagnose hyperthyroidism.
Triiodothyronine (T3) Tests
Also called: T3 Test, T3 Free and Total
This test measures triiodothyronine (T3) in your blood. Your thyroid gland makes T3. T3 plays an important role in the body's control of metabolism (the many processes that control the rate of activity in cells and tissues). The test is mainly used to diagnose hyperthyroidism.
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Use the slider below to see how your results affect your
health.
ng/dL
80
220
Your result is Normal.
The total T3 test measures the T3 that is both attached to proteins and floating free in the blood. A normal result indicates normal thyroid function called euthyroid.
Related conditions
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Use the slider below to see how your results affect your
health.
pg/mL
2
4.4
Your result is Normal.
The free T3 test measures the T3 that is floating free in the blood. The tests for free T3 are generally less accurate than for total T3.
Related conditions
A triiodothyronine (T3) test measures the level of T3 in a sample of your blood. It's used to help diagnose thyroid disease.
Your thyroid is a small, butterfly-shaped gland at the base of your throat. It makes two hormones, T3 and T4 (thyroxine). Hormones are chemical messengers in your bloodstream that control the actions of certain cells or organs.
Thyroid hormones work together to control the way your body uses energy. They affect your weight, heart, body temperature, muscle strength, and even your mood. In children, thyroid hormones affect growth, too.
There are two forms of T3 in your blood:
Free T3 is the active form that enters your tissues where it's needed.
Bound T3 is attached to certain proteins which prevent it from entering your tissues. Most of your T3 is bound.
There are different tests for measuring T3:
A total T3 test measures both bound and free T3 together. Medical experts think that this test is the more accurate way to measure T3.
A free T3 test only measures free T3.
Other names: thyroid function test; total triiodothyronine, free triiodothyronine, FT3, TT3, radioimmunoassay FT3
A T3 test is used to help:
Diagnose hyperthyroidism, a condition in which your thyroid gland makes too much thyroid hormone. The test can also help find out what's causing the condition.
Diagnose pituitary disorders. The pituitary is a pea-sized gland at the base of your brain. It makes a hormone called TSH (thyroid stimulating hormone). TSH tells the thyroid how much T3 and T4 to make. So, abnormal T3 levels may be a sign of a pituitary problem.
Monitor treatment for thyroid disease, including hyperthyroidism and hypothyroidism, which is when the thyroid gland makes to little thyroid hormone.
T3 tests are usually ordered with blood tests that measure T4 and TSH (thyroid stimulating hormone) tests.
You may need a T3 test if you have symptoms of hyperthyroidism (too much thyroid hormone). Symptoms may include:
Anxiety, nervousness, irritability
Weight loss, even though your appetite may increase
Shaky hands, muscle weakness
Sweating or being very sensitive to heat
Irregular heartbeat (arrhythmia)
Frequent bowel movements (poops)
Goiter (an enlarged thyroid gland)
Trouble sleeping and fatigue
You may also need a T3 test if:
You take thyroid hormone medicine to treat a thyroid problem. A T3 test can check whether you're taking the right dose to keep your thyroid hormone levels in a healthy range.
You had abnormal results on a TSH and/or T4 test. Providers usually order these tests first to look into a possible thyroid disorder. If your test results are abnormal or unclear, your provider may use a T3 test to confirm or rule out hyperthyroidism.
T3 testing isn't commonly used to help check for hypothyroidism (too little thyroid hormone). That's because other thyroid tests can diagnose hypothyroidism earlier than a T3 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 T3 blood test. Certain medicines and supplements can affect your test results. Your provider will let you know if you need to stop taking any medicines before your test. But don't stop taking any medicines unless your provider tells you to.
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.
To understand the results of your T3 test, your provider will usually compare them with the results of your TSH and T4 tests. Like T3, T4 tests may measure either free or total T4, but providers usually measure free T4.
Your provider will look for different combinations of high, low, and normal results. Each combination suggests a different thyroid condition. Ask your provider to explain what your test results say about your health.
In general:
Normal T3 levels (free or total) alone do not rule out thyroid disease. But if your TSH and free T4 levels are also normal, you probably don't have a thyroid condition.
High T3 levels (free or total) may mean you have hyperthyroidism (too much thyroid hormone).
High T3 levels with:
Low TSH and high free T4 levels may mean that a problem with your thyroid gland is causing too much thyroid hormone.
Normal or high TSH and high free T4 levels may mean that a pituitary gland condition is causing too much thyroid hormone.
Low T3 levels (free or total) may mean hypothyroidism (too little thyroid hormone).
Low or normal T3 levels with:
High TSH levels and low free T4 levels may mean that a problem with your thyroid gland is causing too little thyroid hormone.
Low TSH and low free T4 levels may mean that a pituitary gland condition is causing too little thyroid hormone.
If you have questions about your results, talk with your provider.
Triiodothyronine (T3) Tests: MedlinePlus Medical Test [accessed on Jan 16, 2024]
T3 test: MedlinePlus Medical Encyclopedia [accessed on Jan 16, 2024]
T3 Test - Testing.com. Nov 29, 2022 [accessed on Jan 16, 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 (9)
Thyroid Gland
The thyroid is a small, butterfly-shaped gland located at the base of the neck, just below the Adam's apple. The thyroid gland produces two main hormones, thyroxine (T4) and triiodothyronine (T3), which play key roles in regulating many aspects of metabolism, the rate at which the cells use energy and carry out chemical processes. The thyroid and the hormones it produces are under the control of a hormone called TSH (thyroid-stimulating hormone) produced by the pituitary gland.
Image by TheVisualMD
Woman's neck region with visible thyroid
The thyroid is a small, butterfly-shaped gland located at the base of the neck. The gland produces two main hormones, thyroxine and triiodothyronine. The hormones help maintain body temperature, heart rate, moods, energy levels, bowel function and rates of fat, protein and carbohydrate metabolism. The thyroid is under the control of a hormone called thyroid-stimulating hormone produced by the pituitary gland; the pituitary gland, in turn, takes its orders from the hypothalamus. Thyroid problems usually fall into one of two categories: hypothroidism, when the gland produces too little hormone; or hyperthroidism, when the gland produces too much.
Image by TheVisualMD
Thyroid problems - most common thyroid problems, symptoms and treatment
Video by Healthchanneltv / cherishyourhealthtv/YouTube
Thyroid gland - What's the function of the thyroid?
Video by Healthchanneltv / cherishyourhealthtv/YouTube
How does the thyroid manage your metabolism? - Emma Bryce
Video by TED-Ed/YouTube
T3 And T4, What Do They Do?
Video by EmpowHER/YouTube
Understanding Thyroid Function Tests
Video by AdonaiDEC/YouTube
Thyroid Blood Tests
Video by Tom Wade MD/YouTube
Understanding Blood Test Video 2: Comprehensive Metabolic Panel
Video by Health in a Nutshell/YouTube
Thyroid Gland
TheVisualMD
Woman's neck region with visible thyroid
TheVisualMD
4:11
Thyroid problems - most common thyroid problems, symptoms and treatment
Healthchanneltv / cherishyourhealthtv/YouTube
1:55
Thyroid gland - What's the function of the thyroid?
Healthchanneltv / cherishyourhealthtv/YouTube
3:37
How does the thyroid manage your metabolism? - Emma Bryce
TED-Ed/YouTube
1:56
T3 And T4, What Do They Do?
EmpowHER/YouTube
6:07
Understanding Thyroid Function Tests
AdonaiDEC/YouTube
6:57
Thyroid Blood Tests
Tom Wade MD/YouTube
5:17
Understanding Blood Test Video 2: Comprehensive Metabolic Panel
Health in a Nutshell/YouTube
Thyroglobulin Test
Thyroglobulin Test
Also called: TGB, Thyroglobulin Tumor Marker
A thyroglobulin test measures the level of thyroglobulin in your blood. Thyroglobulin is a protein made by your thyroid. The test is mostly used to find out if thyroid cancer treatment has worked.
Thyroglobulin Test
Also called: TGB, Thyroglobulin Tumor Marker
A thyroglobulin test measures the level of thyroglobulin in your blood. Thyroglobulin is a protein made by your thyroid. The test is mostly used to find out if thyroid cancer treatment has worked.
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Use the slider below to see how your results affect your
health.
ng/mL
33
Your result is Normal.
Normal results vary based on the laboratory and the method used.
Related conditions
A thyroglobulin test measures the level of thyroglobulin in a sample of your blood. Thyroglobulin is a protein that your thyroid makes. Your thyroid is a small, butterfly-shaped gland in your neck. It makes hormones that control many activities in your body, including your heart rate and how fast you burn calories from food.
A thyroglobulin test is a type of tumor marker test. Tumor markers are substances made by cancer cells and/or by normal cells in response to cancer in your body. Normally, your thyroid releases small amounts of thyroglobulin into your bloodstream. Cells from common types of thyroid cancer (papillary carcinoma and follicular thyroid cancer) also release thyroglobulin.
Thyroglobulin testing is not used to diagnose thyroid cancer because other thyroid diseases that aren't cancer can also affect thyroglobulin levels. But the test is useful after treatment for common thyroid cancers to see if the treatment worked. That's because the goal of treatment is to get rid of all thyroid tissue – both healthy cells and cancer cells. So, if treatment is successful, there should be little or no thyroglobulin in your blood. If thyroglobulin levels remain the same or increase, more cancer treatment may be needed.
A thyroglobulin test is mostly used to:
See if thyroid cancer treatment was successful and guide decisions about more treatment.
Predict how your cancer will behave over time.
See if cancer has returned after successful treatment.
Thyroglobulin tests may also be used to help diagnose hyperthyroidism and hypothyroidism, which are common thyroid conditions that aren't cancer.
You may need a thyroglobulin test before starting treatment for thyroid cancer. Your health care provider will compare these test results to your test results after treatment.
You may also need this test a few weeks after you finish treatment for thyroid cancer. The test helps show whether any thyroid cells remain in your body. If your treatment was successful, you may still need to have your thyroglobulin levels tested from time to time to see if cancer has come back.
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 usually don't need any special preparations for a thyroglobulin test. But you need to avoid taking certain vitamins or supplements so tell your provider about everything you take.
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.
Understanding the results of a thyroglobulin test after treatment can be complicated. The meaning of your results depends on your health history, the type of treatment you had, and the results of other tests. So, it's best to ask your provider to explain what your test results say about your health.
In general, if you were tested after treatment for thyroid cancer:
Very low levels or no thyroglobulin may mean that your cancer treatment has worked to get rid of all thyroid tissue, including cancer. But you will still need more testing over time to make sure.
Thyroglobulin levels that stay high or increase may mean that:
Your treatment did not get rid of all thyroid tissue in your body.
You still have thyroid cancer in your body that has grown and may have spread.
Thyroglobulin levels that were low after treatment but later increased may mean that your thyroid cancer has come back after treatment.
Labs use different methods to measure the amount of thyroglobulin in your blood sample. The test method can affect your results. So, it's important to have your tests done the same way, and usually in the same lab. This allows your provider to compare your results over time. If you have questions about this, talk with your provider.
A thyroglobulin test may not be useful for monitoring your thyroid cancer treatment if you have thyroglobulin antibodies in your blood. These antibodies are proteins that your immune system may make. They attach to thyroglobulin and can make your thyroglobulin levels appear lower than they really are.
Your provider will usually order a thyroid antibody test to find out whether thyroglobulin testing will be useful. If you have thyroglobulin antibodies, other tests will be used to see if your cancer treatment was successful.
Thyroglobulin: MedlinePlus Lab Test Information [accessed on Dec 14, 2022]
Lab Tests Online: Thyroglobulin [accessed on Oct 03, 2018]
Giovanella L et al, Unstimulated high-sensitive thyroglobulin in follow-up of differentiated thyroid cancer patients: a meta-analysis. J Clin Endocrinol Metab. 2013 Nov 27. [accessed on Oct 03, 2018]
Thyroid tests. The American Association of Endocrine Surgeons (AAES). [accessed on Oct 03, 2018]
Thyroglobulin (Tg) and Tg Antibody (TgAb) Testing for Patients Treated for Thyroid Cancers. By Carole Spencer, Ph.D., F.A.C.B President, 2001-2002, American Thyroid Association. [accessed on Oct 03, 2018]
Pellegriti, G. , Scollo, C. , Regalbuto, . C., Attard, M. , Marozzi, P. , Vermiglio, F. , Violi, M. A., Cianci, M. , Vigneri, R. , Pezzino, . V. and Squatrito, S. (2003), The diagnostic use of the rhTSH/thyroglobulin test in differentiated thyroid cancer patients with persistent disease and low thyroglobulin levels. Clinical Endocrinology, 58: 556-561. doi:10.1046/j.1365-2265.2003.01744.x [accessed on Oct 03, 2018]
Indrasena BSH. Use of thyroglobulin as a tumour marker. World Journal of Biological Chemistry. 2017;8(1):81-85. doi:10.4331/wjbc.v8.i1.81. [accessed on Oct 03, 2018]
Medscape: Thyroglobulin (Tg) Measurement [accessed on Oct 03, 2018]
Mayo Clinic: Thyroglobulin, Tumor Marker, Serum [accessed on Oct 03, 2018]
LabCorp: Thyroglobulin, Comprehensive (With Anti-Tg Screen and Reflex to RIA) (Endocrine Sciences) [accessed on Oct 03, 2018]
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 (6)
A hormone called TSH, produced by the pituitary gland, controls the thyroid and the hormones it produces.
The thyroid is a 2-inch, butterfly-shaped gland located at the base of the neck, just below the Adam's apple. The thyroid produces two main hormones, thyroxine (T4) and triiodothyronine (T3), which play key roles in regulating many aspects of metabolism--the rate at which the cells use energy and carry out chemical processes. A hormone called TSH, produced by the pituitary gland, controls the thyroid and the hormones it produces.
Image by TheVisualMD
Thyroglobulin (Tg): Thyroid Cancer
There may be no symptoms of thyroid cancer. If there are symptoms, they can include enlarged lymph nodes in the neck, problems with swallowing, hoarseness or changes in the voice, discomfort in the neck, and a chronic cough. Papillary thyroid cancer (about 80% of all cases) usually grows slowly and may spread to the lymph nodes in the neck. Follicular thyroid cancer (about 15% of cases) also tends to spread slowly, typically to the lungs. Thyroid cancer is treated through surgical removal of all or most of the thyroid, and possibly lymph nodes in the neck as well. Radioactive iodine treatment may be used after surgery. The prognosis for people with thyroid cancer is good: 90% of patients with papillary thyroid cancer and 80% of follicular thyroid cancer patients are alive 10 years after diagnosis.
Image by TheVisualMD
Thyroxine
The structural formula (left) and a space-filling model (right) of (S)-triiodothyronine (T3, also called liothyronine in the pharmaceutical industry)
Image by Benjah-bmm27
Regulation of Body Processes
ADH and aldosterone increase blood pressure and volume. Angiotensin II stimulates release of these hormones. Angiotensin II, in turn, is formed when renin cleaves angiotensinogen. (credit: modification of work by Mikael Häggström)
Image by CNX Openstax (credit: modification of work by Mikael Häggström)
Hashimoto's Disease (Thyroiditis)
Video by UW Health/YouTube
Hashimoto's Thyroiditis Treatment Options
Video by drcheimlich/YouTube
A hormone called TSH, produced by the pituitary gland, controls the thyroid and the hormones it produces.
TheVisualMD
Thyroglobulin (Tg): Thyroid Cancer
TheVisualMD
Thyroxine
Benjah-bmm27
Regulation of Body Processes
CNX Openstax (credit: modification of work by Mikael Häggström)
0:52
Hashimoto's Disease (Thyroiditis)
UW Health/YouTube
5:01
Hashimoto's Thyroiditis Treatment Options
drcheimlich/YouTube
Thyroid Antibody Tests
Thyroid Antibodies Test
Also called: Thyroid Ab, Thyroid Autoantibodies
This test looks for thyroid antibodies in your blood. Thyroid antibodies can be a sign of an autoimmune disorder of the thyroid. These disorders include Hashimoto disease and Grave's disease.
Thyroid Antibodies Test
Also called: Thyroid Ab, Thyroid Autoantibodies
This test looks for thyroid antibodies in your blood. Thyroid antibodies can be a sign of an autoimmune disorder of the thyroid. These disorders include Hashimoto disease and Grave's disease.
A thyroid antibody test measures the level of thyroid antibodies in a sample of your blood. Your thyroid is a small, butterfly-shaped gland in your neck. It makes hormones that control many activities in your body, including your heart rate and how fast you burn calories from food.
Antibodies are proteins that your immune system makes to fight foreign substances, such as viruses and bacteria. But sometimes antibodies attack the healthy cells of your own tissues, and organs by mistake. This is called autoimmune disease.
If antibodies attack your thyroid, they can cause serious thyroid autoimmune diseases:
Hashimoto's disease, also known as Hashimoto's thyroiditis, is the most common cause of hypothyroidism (underactive thyroid). Hypothyroidism happens when your thyroid doesn't make enough thyroid hormones to meet your body's needs. Thyroid hormones affect the way your body uses energy. So, without enough thyroid hormones, many of your body's functions slow down.
Graves' disease is the most common cause of hyperthyroidism (overactive thyroid). With hyperthyroidism, your thyroid makes more thyroid hormones than your body needs. This causes many of your body's functions to speed up.
If your health care provider has diagnosed you with hypothyroidism or hyperthyroidism, thyroid antibody tests can help find out if a thyroid autoimmune disease is causing the problem. There are different tests that check for different types of thyroid antibodies. Your provider will choose tests for you based on your symptoms, the results of other tests, and information about your medical history and family health history.
If tests of your thyroid hormone levels show that your thyroid isn't working properly, your provider may order thyroid antibody tests to see if an autoimmune disease is causing the problem.
Thyroid antibody tests are used to check for different thyroid antibodies that affect your thyroid in different ways. These antibodies include:
Thyroid peroxidase antibodies (TPOAb). High levels of these antibodies are a sign that Hashimoto's disease is causing hypothyroidism.
Thyroglobulin antibodies (TgAb). High levels of these antibodies are a sign of Hashimoto's disease.
Thyrotropin receptor antibodies (TRAb). These antibodies can be a sign of Graves' disease.
You may need a thyroid antibody test if you have symptoms of Hashimoto's disease or Graves' disease. But first, your provider will usually order blood tests to check your thyroid hormone levels to see if you have hyperthyroidism or hypothyroidism. Thyroid hormone tests include T3, T4, and TSH (thyroid-stimulating hormone).
Sometimes these test results, along with your health history, your family, an exam, and your symptoms, are enough to make a diagnosis with thyroid antibody testing.
Symptoms of Hashimoto's disease include:
Weight gain
Fatigue
Hair loss
Low tolerance for cold temperatures
Irregular menstrual periods
Constipation
Depression
Joint pain
Symptoms of Graves' disease include:
Weight loss
Bulging of the eyes
Tremors in the hand
Low tolerance for heat
Trouble sleeping
Anxiety
Increased heart rate
Swollen thyroid, known as goiter
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.
There are no special preparations necessary for a thyroid antibodies blood 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.
Your results may show one of the following:
Negative: no thyroid antibodies were found. This means your thyroid symptoms are probably not caused by an autoimmune disease.
Positive: thyroid antibodies, TPOAb and/or TgAb, were found. This may mean you have Hashimoto's disease. Most people with Hashimoto's disease have high levels of one or both of these types of antibodies.
Positive: thyroid antibodies, TPOAb and/or TRAb, were found. This may mean you have Graves' disease.
The more thyroid antibodies you have, the more likely it is that you have an autoimmune disorder of the thyroid. If you are diagnosed with Hashimoto's disease or Graves' disease, there are medicines you can take to manage your condition.
Thyroid disease can get worse during pregnancy. This can harm both the mother and her unborn baby. If you have ever had thyroid disease and are pregnant, you may be tested for thyroid antibodies along with tests that measure thyroid hormones. Medicines to treat thyroid disease are safe to take during pregnancy.
Thyroid Antibodies: MedlinePlus Medical Test [accessed on Aug 09, 2023]
Thyroid peroxidase (TPO) antibodies are proteins that mistakenly attack the thyroid gland, potentially leading to damage, long-term inflammation (thyroiditis), and disruption of thyroid function.
Thyroid peroxidase (TPO) antibodies are proteins that mistakenly attack the thyroid gland, potentially leading to damage, long-term inflammation (thyroiditis), and disruption of thyroid function.
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Use the slider below to see how your results affect your
health.
(i.U.)/mL
34
Your result is Normal.
Normal value ranges may vary depending on your age, gender, health history, the method used for the test, among other things.
Related conditions
The thyroid is a small, butterfly-shaped gland that is located at the base of your neck. This gland produces certain hormones known as T3 (triiodothyronine) and T4 (thyroxine), which are of utmost importance for the maintenance and regulation of the body’s metabolic system, which is a chemical process that regulates the rate at which the body converts food to energy.
Thyroid peroxidase is an enzyme that can be found inside the thyroid cells and, when damage occurs to these cells, the body produces antibodies against this enzyme.
Usually, the function of antibodies is to protect against external agents that could cause harm or infection, such as bacteria, virus, etc. However, autoantibodies mistakenly attack the healthy cells of the person’s body, causing tissue and organ damage. In this case, thyroid peroxidase antibodies lead to long-term inflammation of the thyroid (thyroiditis) and eventual disruption of thyroid function.
A thyroid peroxidase antibody test measures these antibodies in a sample of your blood.
Your doctor may want to order this test to guide treatment or to help diagnose conditions or diseases that affect the thyroid gland, such as:
Hashimoto thyroiditis.
Graves disease.
This test can also be used to help differentiate autoimmune thyroid disorders from nonautoimmune disorders, such as hypothyroidism (underactive thyroid).
A needle will be used to take a blood sample from a vein in your arm.
No fasting is needed. You may be asked to stop taking supplements containing vitamin B7 (biotin) for at least 12 hours before the test. Make sure to tell your doctor about any medications that you are taking.
You may feel a little sting when the needle is inserted and extracted but, otherwise, it is a quick procedure. You may also experience bruising and a little bleeding, as well as mild soreness for a short amount of time after the extraction.
Normal value ranges may vary depending on your age, gender, health history, the method used for the test, among other things.
Higher-than-normal levels may be due to:
Hashimoto thyroiditis
Graves' disease
Granulomatous thyroiditis
Other autoimmune disorders, such as rheumatoid arthritis, Sjögren syndrome, or systemic lupus erythematosus, among others.
An abnormal result does not necessarily mean that you have a thyroid condition, but, rather, that you have an increased risk of developing thyroid disease in the future.
Antithyroid microsomal antibody: MedlinePlus Medical Encyclopedia [accessed on Oct 05, 2018]
Thyroid Antibodies [accessed on Oct 05, 2018]
006676: Thyroid Peroxidase (TPO) Antibodies | LabCorp [accessed on Oct 05, 2018]
TAB - Clinical: Thyroid Autoantibodies Profile, Serum [accessed on Oct 05, 2018]
TPO - Clinical: Thyroperoxidase (TPO) Antibodies, Serum [accessed on Oct 05, 2018]
Thyroid Autoantibodies Test [accessed on Oct 05, 2018]
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."
Thyroglobulin Antibody Test
Thyroglobulin Antibody Test
Also called: Antithyroglobulin Antibody, TGAb
Thyroglobulin is a protein that helps control metabolic functions and production of hormones T3 and T4 in the thyroid gland. Thyroglobulin antibodies are proteins that mistakenly attack the gland, potentially leading to damage, long-term inflammation (thyroiditis) and disruption of thyroid function.
Thyroglobulin Antibody Test
Also called: Antithyroglobulin Antibody, TGAb
Thyroglobulin is a protein that helps control metabolic functions and production of hormones T3 and T4 in the thyroid gland. Thyroglobulin antibodies are proteins that mistakenly attack the gland, potentially leading to damage, long-term inflammation (thyroiditis) and disruption of thyroid function.
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Use the slider below to see how your results affect your
health.
(i.U.)/mL
4
Your result is Normal.
Normal reference ranges can vary from laboratory to laboratory.
Related conditions
The thyroid is a small, butterfly-shaped gland that is located at the base of your neck. This gland produces certain hormones known as T3 (triiodothyronine) and T4 (thyroxine) which are of utmost importance for the maintenance and regulation of the body’s metabolic system, which is a chemical process that regulates the rate at which the body converts food to energy.
Thyroglobulin is the protein that serves as a precursor for T3 and T4 production in the gland.
Under normal conditions, the antibodies function is to protect against external agents that could cause harm or infection, such as bacteria, virus, etc. However, autoantibodies mistakenly attack the healthy cells of the person’s body, causing tissue and organ damage. In this case, thyroglobulin antibodies lead to long-term inflammation of the thyroid (thyroiditis) and eventual disruption of thyroid function.
A thyroglobulin antibody test measures these antibodies in a sample of your blood.
Your doctor may want to order this test to monitor treatment or to help diagnose conditions or diseases that affect the thyroid gland, such as:
Autoimmune thyroiditis
Hashimoto thyroiditis
Endemic goiter
Recurrence of thyroid cancer
A needle will be used to take a blood sample from a vein in your arm.
No fasting is needed. You may be asked to stop taking supplements containing vitamin B7 (biotin) for at least 12 hours before the test. Make sure to tell your doctor about any medications that you are taking.
You may feel a little sting when the needle is inserted and extracted but otherwise is a quick procedure. You may also experience bruising and a little bleeding, as well as mild soreness for a short amount of time after the extraction.
The normal reference range for thyroglobulin antibodies is less than 4.0 IU/mL.
A positive result means antithyroglobulin antibodies were found in your blood. This can happen as a result of:
Disseminated thyroid carcinoma
Autoimmune hypothyroidism
Hyperthyroidism
Graves’ disease
Hashimoto thyroiditis
Subacute thyroiditis
Underactive thyroid
Systemic lupus erythematosus
Type 1 diabetes
Pregnancy
006685: Thyroglobulin Antibody | LabCorp [accessed on Oct 03, 2018]
Antithyroglobulin antibody test: MedlinePlus Medical Encyclopedia [accessed on Oct 03, 2018]
TGAB - Clinical: Thyroglobulin Antibody, Serum [accessed on Oct 03, 2018]
Thyroglobulin [accessed on Oct 03, 2018]
Thyroid Antibodies [accessed on Oct 03, 2018]
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 (13)
OWH Graves’ Disease Factsheet
Document by Office on Women's Health, U.S. Department of Health and Human Services
Document by Office on Women's Health, U.S. Department of Health and Human Services
Woman with Visible Thyroid
The thyroid is a small, butterfly-shaped gland located at the base of the neck, just below the Adam's apple. The thyroid gland produces two main hormones, thyroxine (T4) and triiodothyronine (T3). The hormones help maintain body temperature, heart rate, moods, energy levels, bowel function and rates of fat, protein and carbohydrate metabolism. The thyroid and the hormones it produces are under the control of a hormone called TSH (thyroid-stimulating hormone) produced by the pituitary gland, which is often referred to as the \"master gland\" because it regulates the activities of other endocrine glands.
Image by TheVisualMD
Thyroid-stimulating Hormone: Thyroid
The thyroid gland produces the hormones thyroxine (T4) and triiodothyronine (T3), which help maintain body temperature, heart rate, moods, and metabolism rates. Levels of T4 and T3 are controlled by TSH (thyroid-stimulating hormone), which is produced by the pituitary gland.
Image by TheVisualMD
Thyroid Gland
The thyroid is a small, butterfly-shaped gland located at the base of the neck, just below the Adam`s apple. Hormones produced by the thyroid gland have an enormous impact on many aspects of metabolism.
Drawing of the head and neck with the thyroid, pituitary gland, TSH, and T3–T4 labeled. Arrows show the direction of TSH from the pituitary gland to the thyroid gland and of T3–T4 from the thyroid to the pituitary gland
The thyroid gland’s production of thyroid hormones (T3 and T4) is regulated by thyroid-stimulating hormone (TSH), which is made by the pituitary gland.
Image by NIDDK Image Library
Importance of Thyroid Gland
The thyroid and the hormones it produces, for example, are under control of a hormone called TSH (thyroid-stimulating hormone), which is produced by the pituitary gland. The pituitary gland is often referred to as the "master gland" because it regulates the activities of other endocrine glands. The pituitary gland, however, takes its orders from the hypothalamus, which decides which particular hormones the pituitary should release and when.
Image by TheVisualMD
Endocrine Glands
The pituitary gland is located at (a) the base of the brain and (b) connected to the hypothalamus by the pituitary stalk. (credit a: modification of work by NCI; credit b: modification of work by Gray’s Anatomy)
Image by CNX Openstax
Thyroid problems - most common thyroid problems, symptoms and treatment
Video by Healthchanneltv / cherishyourhealthtv/YouTube
Thyroid gland - What's the function of the thyroid?
Video by Healthchanneltv / cherishyourhealthtv/YouTube
What Is A Thyroid Nodule?
Video by Swedish/YouTube
How a thyroid gland can become underactive
Video by Bupa Health UK/YouTube
OWH Graves’ Disease Factsheet
Office on Women's Health, U.S. Department of Health and Human Services
Office on Women's Health, U.S. Department of Health and Human Services
Woman with Visible Thyroid
TheVisualMD
Thyroid-stimulating Hormone: Thyroid
TheVisualMD
Thyroid Gland
TheVisualMD
Thyroid Gland
CNX Openstax
Drawing of the head and neck with the thyroid, pituitary gland, TSH, and T3–T4 labeled. Arrows show the direction of TSH from the pituitary gland to the thyroid gland and of T3–T4 from the thyroid to the pituitary gland
NIDDK Image Library
Importance of Thyroid Gland
TheVisualMD
Endocrine Glands
CNX Openstax
4:11
Thyroid problems - most common thyroid problems, symptoms and treatment
Healthchanneltv / cherishyourhealthtv/YouTube
1:55
Thyroid gland - What's the function of the thyroid?
Thyrotropin, also known as thyroid-stimulating hormone (TSH), is a hormone that stimulates the production of hormones T3 and T4 in the thyroid gland. Thyrotropin receptor antibodies are proteins that mistakenly attack the gland, potentially leading to damage and disruption of thyroid function.
Thyrotropin, also known as thyroid-stimulating hormone (TSH), is a hormone that stimulates the production of hormones T3 and T4 in the thyroid gland. Thyrotropin receptor antibodies are proteins that mistakenly attack the gland, potentially leading to damage and disruption of thyroid function.
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Use the slider below to see how your results affect your
health.
(i.U.)/L
1.75
Your result is Normal.
Normal reference ranges can slightly vary from laboratory to laboratory.
Related conditions
Thyrotropin, also known as thyroid-stimulating hormone (TSH), is made in the pituitary gland which is located in the brain. Thyrotropin stimulates the thyroid gland to secrete other hormones known as T3 (triiodothyronine) and T4 (thyroxine) which are of utmost importance for the maintenance and regulation of the body’s metabolic system, which is a chemical process that regulates the rate at which the body converts food to energy.
Usually, the antibodies function is to protect against external agents that could cause harm or infection, such as bacteria, virus, etc. However, autoantibodies mistakenly attack the healthy cells of the person’s body, causing tissue and organ damage.
In this case, thyrotropin (TSH)-receptor antibodies (TRAb) influence the function and growth of the gland, leading to long-term inflammation of the thyroid (thyroiditis) and eventual disruption of thyroid function.
A thyrotropin receptor antibody test measures these antibodies in a sample of your blood.
Your doctor may want to order this test to monitor treatment or to help diagnose conditions or diseases that affect the thyroid gland, especially in the following cases:
To determine the cause of thyrotoxicosis.
As an aid in the diagnosis of Graves’ disease in people with normal thyroid function tests.
To monitor treatment for Graves’ disease.
In pregnant women, to predict neonatal thyrotoxicosis in the fetus.
To predict relapse of hyperthyroidism.
A needle will be used to take a blood sample from a vein in your arm.
No fasting is needed. You may be asked to stop taking supplements containing vitamin B7 (biotin) for at least 12 hours before the test. Make sure to tell your doctor about any medications that you are taking.
You may feel a little sting when the needle is inserted and extracted but otherwise is a quick procedure. You may also experience bruising and a little bleeding, as well as mild soreness for a short amount of time after the extraction.
The normal reference range for thyrotropin receptor antibodies is less than 1.75 units/L.
A higher-than-normal or a positive result means that elevated amounts of thyrotropin receptor antibodies were found in your blood. This can happen as a result of:
Hyperthyroidism
Graves’ disease
Thyrotoxicosis
Neonatal thyrotoxicosis
Thyrotropin receptor antibodies: advances and importance of detection techniques in thyroid diseases. - PubMed - NCBI [accessed on Oct 04, 2018]
THYRO - Clinical: Thyrotropin Receptor Antibody, Serum [accessed on Oct 04, 2018]
010314: Thyrotropin Receptor Antibody, Serum | LabCorp [accessed on Oct 04, 2018]
Clinical Utility of TSH Receptor Antibodies | The Journal of Clinical Endocrinology & Metabolism | Oxford Academic [accessed on Oct 04, 2018]
DEFINE_ME [accessed on Oct 04, 2018]
Official Journal of the American Thyroid Association. Thyroid Autoantibodies (TPOAb, TgAb and TRAb). Thyroid. 2003;13(1). [accessed on Oct 04, 2018]
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."
Imaging Tests
A) Normal thyroid, B) Graves disease C) Plummers disease, D) Toxic adenoma, E) Thyroiditis
Image by Petros Perros
A) Normal thyroid, B) Graves disease C) Plummers disease, D) Toxic adenoma, E) Thyroiditis
5 different scintigramms taken from thyroids with different syndromes: A) Normal thyroid, B) Graves disease, diffuse increased uptake in both thyroid lobes, C) Plummers disease (TMNG, toxic multinodular goitre), D) Toxic adenoma, E) Thyroiditis. Marker 99Tc
Image by Petros Perros
What Imaging Tests Do Doctors Use to Diagnose and Find the Cause of Thyroid Disease?
Your health care professional may order one or more imaging tests to diagnose and find the cause of thyroid disease. A trained technician usually does these tests in your doctor’s office, outpatient center, or hospital. A radiologist, a doctor who specializes in medical imaging, reviews the images and sends a report for your health care professional to discuss with you.
Ultrasound
Ultrasound of the thyroid is most often used to look for, or more closely at, thyroid nodules. Thyroid nodules are lumps in your neck. Ultrasound can help your doctor tell if the nodules are more likely to be cancerous.
For an ultrasound, you will lie on an exam table and a technician will run a device called a transducer over your neck. The transducer bounces safe, painless sound waves off your neck to make pictures of your thyroid. The ultrasound usually takes around 30 minutes.
During an ultrasound, a transducer bounces sound waves off the neck to make images of the thyroid.
Thyroid scan
Health care professionals use a thyroid scan to look at the size, shape, and position of the thyroid gland. This test uses a small amount of radioactive iodine to help find the cause of hyperthyroidism and check for thyroid nodules. Your health care professional may ask you to avoid foods high in iodine, such as kelp, or medicines containing iodine for a week before the test.
For the scan, a technician injects a small amount of radioactive iodine or a similar substance into your vein. You also may swallow the substance in liquid or capsule form. The scan takes place 30 minutes after an injection, or up to 24 hours after you swallow the substance, so your thyroid has enough time to absorb it.
During the scan, you will lie on an exam table while a special camera takes pictures of your thyroid. The scan usually takes 30 minutes or less.
Thyroid nodules that make too much thyroid hormone show up clearly in the pictures. Radioactive iodine that shows up over the whole thyroid could mean you have Graves’ disease.
Even though only a small amount of radiation is needed for a thyroid scan and it is thought to be safe, you should not have this test if you are pregnant or breastfeeding.
Radioactive iodine uptake test
A radioactive iodine uptake test, also called a thyroid uptake test, can help check thyroid function and find the cause of hyperthyroidism. The thyroid “takes up” iodine from the blood to make thyroid hormones, which is why this is called an uptake test. Your health care professional may ask you to avoid foods high in iodine, such as kelp, or medicines containing iodine for a week before the test.
For this test, you will swallow a small amount of radioactive iodine in liquid or capsule form. During the test, you will sit in a chair while a technician places a device called a gamma probe in front of your neck, near your thyroid gland. The probe measures how much radioactive iodine your thyroid takes up from your blood. Measurements are often taken 4 to 6 hours after you swallow the radioactive iodine and again at 24 hours. The test takes only a few minutes.
If your thyroid collects a large amount of radioactive iodine, you may have Graves’ disease, or one or more nodules that make too much thyroid hormone. You may have this test at the same time as a thyroid scan.
Even though the test uses a small amount of radiation and is thought to be safe, you should not have this test if you are pregnant or breastfeeding.
Source: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Additional Materials (2)
Pheochromocytoma
Pheochromocytoma (dark circular shadow near body center) localized by MIBG scintigraphy. Front and back views also show radioiodine collection in thyroid (neck) and bladder (pelvis)
Image by Drahreg01
Thyroglobulin (Tg): Thyroid Cancer
There may be no symptoms of thyroid cancer. If there are symptoms, they can include enlarged lymph nodes in the neck, problems with swallowing, hoarseness or changes in the voice, discomfort in the neck, and a chronic cough. Papillary thyroid cancer (about 80% of all cases) usually grows slowly and may spread to the lymph nodes in the neck. Follicular thyroid cancer (about 15% of cases) also tends to spread slowly, typically to the lungs. Thyroid cancer is treated through surgical removal of all or most of the thyroid, and possibly lymph nodes in the neck as well. Radioactive iodine treatment may be used after surgery. The prognosis for people with thyroid cancer is good: 90% of patients with papillary thyroid cancer and 80% of follicular thyroid cancer patients are alive 10 years after diagnosis.
Image by TheVisualMD
Pheochromocytoma
Drahreg01
Thyroglobulin (Tg): Thyroid Cancer
TheVisualMD
Thyroid Ultrasound
Thyroid Ultrasound
Also called: Thyroid Sonogram, Ultrasound - Thyroid
A thyroid ultrasound is a noninvasive, painless, and risk-free imaging test in which an ultrasound machine is used to evaluate your thyroid gland and determine if it has any abnormality.
Thyroid Ultrasound
Also called: Thyroid Sonogram, Ultrasound - Thyroid
A thyroid ultrasound is a noninvasive, painless, and risk-free imaging test in which an ultrasound machine is used to evaluate your thyroid gland and determine if it has any abnormality.
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Use the slider below to see how your results affect your
health.
Your result is Normal.
A normal result will show that that the thyroid gland is in the proper location, and has a correct size and shape.
Related conditions
The thyroid is a small, butterfly-shaped gland that is located at the base of your neck. This gland produces certain hormones known as T3 (triiodothyronine) and T4 (thyroxine) which are of utmost importance for the maintenance and regulation of your metabolism, which is a chemical process that regulates the rate at which the body converts food to energy.
A thyroid ultrasound is an imaging test that uses sound waves to create images of parts of your body. It is used to evaluate your thyroid’s shape, size, and position.
Your doctor may want to order this test after a physical exam has shown abnormalities in your thyroid gland, including:
A growth or irregularities on your thyroid gland, which can indicate goiter or nodules.
Investigate abnormal lymph nodes near your thyroid gland.
To evaluate changes in the thyroid gland due to surgery, medication, radiotherapy or chemotherapy.
Ultrasound is also often used to guide the needle when a thyroid biopsy is needed to check for thyroid cancer. In that case, a needle is used to draw out a small sample of tissue from the thyroid gland or nodule.
You will be asked to lie down on your back with your neck slightly stretched on a pillow. Then, a healthcare practitioner will apply a water-based gel on the skin of the front of your neck and then place a small probe, called a transducer, to visualize your thyroid gland on a screen.
The procedure usually takes between 10 and 30 minutes, and there is no need for an anesthetic because it’s painless.
No special preparations are needed.
There are no risks related to a thyroid ultrasound test. You are not exposed to radiation during this test.
Normal
Normal ultrasound results will show that the thyroid gland is in the proper location, and has a correct size and shape.
Abnormal
Abnormalities in the gland’s shape, size, or location may indicate:
Goiter (enlargement of the thyroid gland)
Thyroid nodules
Thyroid tumor
Thyroid cysts (nodules filled with fluid)
Thyroiditis, or inflammation of the thyroid (if a biopsy is done)
A thyroid ultrasound may be done for a number of reasons, including helping find suspicious areas that have any reasonable chance of being cancerous. However, an ultrasound alone cannot make the diagnosis of cancer. This test will usually help determine that the nodule has a low chance of being cancerous (has characteristics of a benign nodule), or that it has some characteristics of a cancerous nodule, and therefore a biopsy is indicated.
Thyroid ultrasound: MedlinePlus Medical Encyclopedia [accessed on Oct 05, 2018]
Thyroid Ultrasound [accessed on Oct 05, 2018]
Thyroid ultrasound [accessed on Oct 05, 2018]
Thyroid Nodule Ultrasound: What is it, what does it tell me? - Quick, painless, inexpensive, and accurate [accessed on Oct 05, 2018]
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."
Nodule Tests
Ultrasound Scan of a Thyroid Nodule
Image by Nevit Dilmen/Wikimedia
Ultrasound Scan of a Thyroid Nodule
Ultrasound artifacts showing a "comet tail" from a colloid nodule indicate a benign nodule.
Image by Nevit Dilmen/Wikimedia
What Tests Do Doctors Use If I Have a Thyroid Nodule?
If your health care professional finds a nodule or lump in your neck during a physical exam or on thyroid imaging tests, you may have a fine needle aspiration biopsy to see if the lump is cancerous or noncancerous.
For this test, you will lie on an exam table and slightly bend your neck backward. A technician will clean your neck with an antiseptic and may use medicine to numb the area. An endocrinologist who treats people with endocrine gland problems like thyroid disease, or a specially trained radiologist, will place a needle through the skin and use ultrasound to guide the needle to the nodule. Small samples of tissue from the nodule will be sent to a lab for testing. This procedure usually takes less than 30 minutes. Your health care professional will talk with you about the test result when it is available.
Source: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Additional Materials (2)
Follicular Cell of Thyroid Gland
The thyroid is a small, butterfly-shaped gland located at the base of the neck, just below the Adam's apple. The thyroid gland produces two main hormones, thyroxine (T4) and triiodothyronine (T3). The hormones help maintain body temperature, heart rate, moods, energy levels, bowel function and rates of fat, protein and carbohydrate metabolism. The thyroid contains spherical follicles that absorb iodine ions from the blood for use in the production of T4 and T3. Iodine deficiency, rare in the U.S., affects two billion people worldwide and is the leading preventable cause of mental retardation.
Image by TheVisualMD
Thyroid Follicle
The thyroid is a small, butterfly-shaped gland located at the base of the neck, just below the Adam's apple. The thyroid gland produces two main hormones, thyroxine (T4) and triiodothyronine (T3). The hormones help maintain body temperature, heart rate, moods, energy levels, bowel function and rates of fat, protein and carbohydrate metabolism. The thyroid contains spherical follicles that absorb iodine ions from the blood for use in the production of T4 and T3. Iodine deficiency, rare in the U.S., affects two billion people worldwide and is the leading preventable cause of mental retardation.
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Follicular Cell of Thyroid Gland
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Thyroid Follicle
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Thyroid Biopsy
Thyroid Biopsy
Also called: Thyroid Fine Needle Biopsy, Thyroid Fine Needle Aspiration Biopsy, Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid
This test tells whether thyroid nodules have normal cells in them. Your doctor may numb an area on your neck. Your doctor will then stick a very thin needle into the thyroid to take out some cells and fluid. A doctor will then look at the cells under a microscope to see if they are normal. Cells that are not normal could mean thyroid cancer.
Thyroid Biopsy
Also called: Thyroid Fine Needle Biopsy, Thyroid Fine Needle Aspiration Biopsy, Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid
This test tells whether thyroid nodules have normal cells in them. Your doctor may numb an area on your neck. Your doctor will then stick a very thin needle into the thyroid to take out some cells and fluid. A doctor will then look at the cells under a microscope to see if they are normal. Cells that are not normal could mean thyroid cancer.
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Your result is TBS I — non-diagnostic.
TBS I: non-diagnostic or unsatisfactory — This means that there are not enough thyroid follicular cells in the sample to make a diagnosis. Non-diagnostic samples can also occur when only cyst fluid is taken out, and for other reasons, such as the presence of too much blood. In these cases, the biopsy should be repeated, and if non-diagnostic a second time, consideration is given to a third biopsy, monitoring, or surgery.
Related conditions
This test tells whether thyroid nodules have normal cells in them. Your doctor may numb an area on your neck. Your doctor will then stick a very thin needle into the thyroid to take out some cells and fluid. A doctor will then look at the cells under a microscope to see if they are normal. Cells that are not normal could mean thyroid cancer.
Thyroid Tests | NIDDK [accessed on May 09, 2022]
https://www.womenshealth.gov/a-z-topics/thyroid-disease [accessed on May 09, 2022]
https://www.thyroid.org/fna-thyroid-nodules/ [accessed on May 09, 2022]
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."
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Thyroid Tests
The thyroid is a gland in your neck that makes thyroid hormones. Thyroid hormones control the rate of many activities in your body, like how fast you burn calories and how fast your heart beats. Thyroid tests check how well your thyroid is working. Read about blood and imaging tests that doctors use to diagnose and monitor thyroid diseases.