The two bone marrow tests are aspiration and biopsy. Aspiration is usually done first to collect a small amount of bone marrow fluid through a needle. Often a biopsy test is done at the same time as the aspiration test. A biopsy test collects a small amount of bone marrow tissue through a larger needle. These tests most commonly are done to help find the cause of low or high blood cell counts. They also play an important role in monitoring how well treatments for certain types of cancers, such as leukemia or lymphoma, are working.

Before this procedure, be sure to tell your doctor about current medicines you are taking, known allergies to medicines, if you are pregnant, or if you have a bleeding disorder. This test may not be safe for people with certain bleeding disorders such as hemophilia.

Bone marrow tests can be done in a hospital, doctor’s office, or other health care facility. You will be awake for your test and may be given medicine to relax you during the test. You will lie on your side or stomach. Your doctor will clean and numb the top ridge of the back of a hipbone, called the posterior iliac crest, where the needle will be inserted. You may feel a brief, sharp pain when the needle is inserted and when the bone marrow is aspirated. The bone marrow samples will be studied in a laboratory.

After your test, you will have a small bandage on the site where the needle was inserted. Most people go home the same day. You will need a ride home if you received medicines to relax you during the test. You may have mild discomfort for about a week. Your doctor may have you take an over-the-counter pain medicine. Call your doctor if you are in severe pain or if you develop a fever, redness, swelling, or discharge at the needle injection site.

Your doctor may recommend bone marrow tests if he or she thinks you have a blood or bone marrow disease or condition, such as:

• Myelodysplastic (MI-eh-lo-dis-PLAST-ik) syndrome. This is a group of diseases in which your bone marrow doesn't make enough normal blood cells.
• Neutropenia (NU-tro-PE-ne-ah). This is a condition in which you have a lower than normal number of white blood cells in your blood.
• Anemia (uh-NEE-me-uh). Anemia occurs if you have a lower than normal number of red blood cells. The condition also can occur if your red blood cells don't have enough of an iron-rich protein that carries oxygen from the lungs to the rest of the body.
• Aplastic anemia. This type of anemia occurs if your bone marrow doesn't make enough new blood cells (red blood cells, white blood cells, and platelets). Aplastic anemia is a rare, but serious condition.
• Myelofibrosis. This is a serious bone marrow disorder that disrupts normal production of blood cells and leads to severe anemia.
• Thrombocytopenia (THROM-bo-si-toe-PE-ne-ah). This is a group of conditions in which your body doesn't make enough platelets and your blood doesn't clot as it should.
• Essential thrombocythemia (THROM-bo-si-THE-me-ah). This is a disease in which your bone marrow makes too many blood cells, especially platelets.
• Leukemia. This is a cancer of the white blood cells. Types of leukemia include acute and chronic leukemias and multiple myeloma.

Your doctor also may recommend bone marrow tests if you have another type of cancer. Examples include breast cancer that has spread to the bone or Hodgkin's and non-Hodgkin's lymphomas (cancers of a certain type of white blood cell).

Bone marrow tests help show what stage the cancer is in. That is, the tests help doctors know how serious the cancer is and how much it has spread in the body.

Bone marrow tests also can show what's causing a fever. Doctors may recommend the tests for people who have diseases that affect the immune system. The tests also are used for patients who may have uncommon bacterial infections.

Before having bone marrow tests, a doctor, nurse, or physician assistant will explain the testing process and procedure and answer questions you might have.

Let your health care team know:

• Whether you're allergic to any medicines
• Whether you have a bleeding disorder
• What medicines you're taking (you might have to stop taking some medicines, such as blood-thinning medicines, before having bone marrow tests)
• Whether you're pregnant

Before the tests, you may be given medicine to help you relax. This medicine makes you sleepy, so you likely won't be able to drive after the test. Thus, your health care team may advise you to arrange a ride home.

Bone marrow tests usually take about 30 minutes. The tests can be done in a hospital, doctor's office, or other health care facility.

Bone marrow tests generally are done on the pelvic bone. In most people, part of this bone is accessible on the lower back. If your doctor uses that part of the pelvic bone, you'll lie on your side or stomach for the test. Aspiration might be done on the breastbone.

Medicine will be used to numb the area where your doctor will insert the needle. Although you'll be awake during the tests, the medicine helps reduce pain.

If you're very nervous or anxious, your doctor may give you medicine to help you relax or sleep. If so, your health care team will closely check your breathing, heart rate, and blood pressure during the tests.

The area on your body where your doctor will insert the needle is cleaned and draped with a cloth. Your doctor will see only the site where the needle is inserted. He or she will make a small incision (cut) in your skin. This makes it easier to insert the needle into the bone. After the test, you might need stitches to close the cut.

For bone marrow aspiration, your doctor will insert the needle into the marrow and remove a sample of fluid bone marrow. You may feel a brief, sharp pain. The fluid that's removed from the bone marrow will be taken to a laboratory and studied under a microscope.

If your doctor decides to do a bone marrow biopsy, it will be done after the aspiration. For the biopsy, your doctor will use a needle to remove a sample of bone marrow tissue. Thin sections of this tissue will be studied under a microscope.

During both tests, it's important for you to remain still and as relaxed as possible (if you're awake).

Bone marrow tests are safe for most people. Complications are rare, but can occur. For example, some people develop bleeding or infections.

To prevent bleeding from the site where the needle was inserted, don't do any heavy lifting or vigorous exercise for a few days after the tests.

To prevent infections, don't shower or bathe for the first day after the tests. After 24 hours, you can take off the bandage. Call your doctor if you develop a fever, have a lot of pain, or see redness, swelling, or discharge at the site. These are signs of infection.

Expect mild discomfort for about a week. Your doctor may tell you to take an over-the-counter pain medicine.

Bone marrow tests might not be safe for people who have certain bleeding disorders, such as hemophilia. Your doctor can tell you whether bone marrow tests are safe for you.

Bone marrow tests show whether your bone marrow is making enough healthy blood cells. If it's not, the results can tell your doctor which cells are unhealthy and why.

Bone marrow tests are an important medical tool. They're used to diagnose many blood and bone marrow disorders, including anemia and certain kinds of cancer.

Bone marrow tests also are used to find out how severe cancer is and how much it has spread throughout the body. The tests also help doctors find the cause of fevers and infections.

Your doctor will combine information from your bone marrow tests with information from a physical exam, blood tests, and other tests, such as imaging scans and x rays. This information will help your doctor diagnose your condition and plan how to treat it.

After the bone marrow tests, a nurse will hold a bandage on the site where the needle was inserted until the bleeding stops. Then he or she will put a smaller bandage on the site.

Most people can go home the same day as the tests. If you received medicine to help you relax during the tests, you may need to arrange a ride home.

After 24 hours, you can take off the bandage. Call your doctor if you develop a fever, have a lot of pain, or see redness, swelling, or discharge at the site. These are signs of infection.

Expect mild discomfort for about a week. Your doctor may tell you to take an over-the-counter pain medicine.