What Are Bone Marrow Tests?

Bone marrow tests are used to check whether your bone marrow is healthy. These tests also show whether your bone marrow is making normal amounts of blood cells.

Bone marrow is the sponge-like tissue inside the bones. It contains stem cells that develop into the three types of blood cells that the body needs:

• Red blood cells carry oxygen through the body.
• White blood cells fight infection.
• Platelets (PLATE-lets) stop bleeding.

Another type of stem cell, called an embryonic (em-bre-ON-ik) stem cell, can develop into any type of cell in the body. These cells aren't found in bone marrow.

Overview

Doctors use bone marrow tests to diagnose blood and bone marrow diseases and conditions, including:

• Conditions in which a person produces too few or too many of certain types of blood cells
• Problems with the structure of red blood cells
• Bone marrow disorders, such as myelofibrosis (MI-e-lo-fi-BRO-sis)
• Some cancers, such as leukemia (lu-KE-me-ah)

Bone marrow tests also help doctors figure out how severe a cancer is and how much it has spread in the body. The tests also are used to diagnose fevers and infections.

The two bone marrow tests are aspiration (as-pi-RA-shun) and biopsy.

Bone marrow aspiration usually is done first. For this test, your doctor removes a small amount of fluid bone marrow through a needle. He or she may have some idea of what the problem is, and the sample gives him or her useful information about the cells in the marrow.

A bone marrow biopsy is a followup test. It's done when an aspiration doesn't give needed information. Or, it's done if your doctor wants to examine the bone marrow structure itself. For a bone marrow biopsy, your doctor removes a small amount of bone marrow tissue through a larger needle.

Outlook

Bleeding and infection are the most common risks of bone marrow tests, but they're rare. The tests are fairly simple, and they're safe for most people.

In some cases, these tests aren't safe for people who have certain bleeding disorders, such as hemophilia. Your doctor can tell you whether a bone marrow test is safe for you.

Who Needs Bone Marrow Tests?

Your doctor may recommend bone marrow tests if he or she thinks you have a blood or bone marrow disease or condition. These diseases and conditions include:

• Myelodysplastic (MI-e-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-eh). This is a condition in which you have a lower than normal number of red blood cells, or 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. Bone marrow tests also are used to diagnose aplastic anemia. This is a rare and serious condition in which bone marrow stops making enough new blood cells.
• Myelofibrosis. This is a serious bone marrow disorder that disrupts normal production of blood cells and leads to severe anemia.
• Thrombocytopenia (THROM-bo-si-to-PE-ne-ah). This group of conditions occurs when 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 other types of cancer. These may include breast cancer that has spread to the bone or Hodgkin's and non-Hodgkin's lymphomas (cancers of a particular 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. The tests may be used for people who have diseases in which their immune systems aren't working properly. The tests also are used for patients who may have uncommon bacterial infections.

What To Expect During Bone Marrow Tests

Bone marrow aspiration and biopsy take about 20 minutes each. Before the tests, a doctor or nurse will explain the testing process. Your breathing, heart rate, and any pain will be closely checked during the test.

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

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 numb the skin at the site and then make a small incision (cut). This makes it easier to insert the needle into the bone. Stitches may be needed to close the cut after the test.

For bone marrow aspiration, your doctor will insert the needle into the marrow and remove a small amount 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 lab 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 small amount of the 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.

What To Expect After Bone Marrow Tests

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.

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.

What Do Bone Marrow Tests Show?

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 tool. They're used to diagnose a variety of blood and bone marrow disorders, including anemia and certain kinds of cancer.

Bone marrow tests also are used to find out how serious a cancer is and how much it has spread to other areas of the body. The tests also help doctors determine the cause of fevers and infections.

Your doctor will combine information from your bone marrow test 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.

What Are the Risks of Bone Marrow Tests?

Bleeding and infection are the most common risks of bone marrow tests, but they're rare.

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 infection, 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 are safe for most people. In some cases, these tests aren't safe for people who have certain bleeding disorders, such as hemophilia. Your doctor can tell you whether bone marrow tests are safe for you.

Key Points

• Bone marrow tests are used to check whether your bone marrow is healthy. These tests show whether your bone marrow is making normal amounts of blood cells.
• Bone marrow is the sponge-like tissue inside the bones. It contains stem cells that develop into the three types of blood cells that the body needs: red blood cells, white blood cells, and platelets.
• Bone marrow tests help doctors diagnose blood and bone marrow diseases and conditions.
• Bone marrow tests also are done to help doctors determine how severe a person's cancer is and how much it has spread in the body. These tests also are used to diagnose fevers and infections.
• The two bone marrow tests are aspiration and biopsy. For these tests, your doctor uses a needle to remove a small amount of fluid bone marrow (for aspiration) or bone marrow tissue (for biopsy). A biopsy is a followup test that's done when an aspiration doesn't give needed information or when your doctor wants to look at the bone marrow structure.
• Bone marrow tests take about 20 minutes each. You may feel a brief, sharp pain as the needle is inserted into the bone marrow. It's important for you to remain still and as relaxed as possible during the tests.
• 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.
• 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 treatment.
• Bleeding and infection are the most common complications of bone marrow tests, but they're rare. In some cases, these tests aren't safe for people who have certain bleeding disorders, such as hemophilia. Your doctor can tell you whether bone marrow tests are safe for you.

Links to Other Information About Bone Marrow Tests

Non-NHLBI Resources

• Bone Marrow Tests (MedlinePlus)

Clinical Trials

• Current Research (ClinicalTrials.gov)
• NHLBI Pediatric Clinical Trials