Bone marrow is the spongy tissue inside some of your bones, such as your hip and thigh bones. It contains immature cells called hematopoietic or blood-forming cells. A bone marrow aspiration (BMA) is a procedure to remove a small amount of bone marrow from your body. This sample can be used for tests or for a bone marrow transplant. You may need a BMA if you have certain blood disorders, such as leukemia or lymphoma. Your doctor may also recommend a BMA to check how well your bone marrow is working. The most common place to do a BMA is in the hip bone. This bone has a large amount of bone marrow and is easy to access. The procedure is also sometimes done in the breastbone. Before a BMA, your doctor will likely do a physical exam and ask about your medical history. You may also have blood tests. Tell your doctor if you're pregnant or think you might be pregnant. You may not be able to have the procedure if you are pregnant. You will likely be asked to sign a consent form that says you understand the risks of the procedure and agree to have it done. Risks of a BMA include: - Bleeding - Infection - Pain - Bruising You may be given medicine to help prevent pain and bleeding. During a BMA, you will lie on your stomach or side. Your doctor will clean the skin over the area where the needle will go in. Then, they will numb the area with a local anesthetic. Next, your doctor will insert a needle into the bone marrow. They will use a syringe to suction out a small amount of bone marrow. You may feel pressure during this part of the procedure. The sample will be sent to a lab for testing. The results will be available in a few days. A BMA is usually an outpatient procedure, which means you can go home the same day. You may need someone to drive you home after the procedure. You may have some pain and bruising at the site where the needle was inserted. You can take over-the-counter pain medicine for this. Call your doctor if you have a fever, chills, or redness, swelling, or drainage at the needle site. These could be signs of an infection.