What are bone marrow tests?

Bone marrow is a soft, spongy tissue found in the center of most bones. Bone marrow makes different types of blood cells. These include:

• Red blood cells (also called erythrocytes), which carry oxygen from your lungs to every cell in your body
• White blood cells (also called leukocytes), which help you fight infections
• Platelets, which help with blood clotting.

Bone marrow tests check to see if your bone marrow is working correctly and making normal amounts of blood cells. The tests can help diagnose and monitor various bone marrow disorders, blood disorders, and certain types of cancer. There are two types of bone marrow tests:

• Bone marrow aspiration, which removes a small amount of bone marrow fluid
• Bone marrow biopsy, which removes a small amount of bone marrow tissue

Bone marrow aspiration and bone marrow biopsy tests are usually performed at the same time.

Other names: bone marrow examination

What are they used for?

Bone marrow tests are used to:

• Find out the cause of problems with red blood cells, white bloods, or platelets
• Diagnose and monitor blood disorders, such as anemia, polycythemia vera, and thrombocytopenia
• Diagnose bone marrow disorders
• Diagnose and monitor certain types of cancers, including leukemia, multiple myeloma, and lymphoma
• Diagnose infections that may have started or spread to the bone marrow

Why do I need a bone marrow test?

Your health care provider may order a bone marrow aspiration and a bone marrow biopsy if other blood tests show your levels of red blood cells, white blood cells, or platelets are not normal. Too many or too few of these cells may mean you have a medical disorder, such as cancer that starts in your blood or bone marrow. If you are being treated for another type of cancer, these tests can find out if the cancer has spread to your bone marrow.

What happens during a bone marrow test?

Bone marrow aspiration and bone marrow biopsy tests are usually given at the same time. A doctor or other health care provider will perform the tests. Before the tests, the provider may ask you to put on a hospital gown. The provider will check your blood pressure, heart rate, and temperature. You may be given a mild sedative, a medicine that will help you relax. During the test:

• You'll lie down on your side or your stomach, depending on which bone will be used for testing. Most bone marrow tests are taken from the hip bone.
• Your body will be covered with cloth, so that only the area around the testing site is showing.
• The site will be cleaned with an antiseptic.
• You will get an injection of a numbing solution. It may sting.
• Once the area is numb, the health care provider will take the sample. You will need to lie very still during the tests.
• For a bone marrow aspiration, which is usually performed first, the health care provider will insert a needle through the bone and pull out bone marrow fluid and cells. You may feel a sharp but brief pain when the needle is inserted.
• For a bone marrow biopsy, the health care provider will use a special tool that twists into the bone to take out a sample of bone marrow tissue. You may feel some pressure on the site while the sample is being taken.
• It takes about 10 minutes to perform both tests.
• After the test, the health care provider will cover the site with a bandage.
• Plan to have someone drive you home, since you may be given a sedative before the tests, which may make you drowsy.

Will I need to do anything to prepare for the test?

You will be asked to sign a form that gives permission to perform bone marrow tests. Be sure to ask your provider any questions you have about the procedure.

Are there any risks to the test?

Many people feel a little uncomfortable after bone marrow aspiration and bone marrow biopsy testing. After the test, you may feel stiff or sore at the injection site. This usually goes away in a few days. Your health care provider may recommend or prescribe a pain reliever to help. Serious symptoms are very rare, but may include:

• Long-lasting pain or discomfort around the injection site
• Redness, swelling, or excessive bleeding at the site
• Fever

If you have any of these symptoms, call your health care provider.