Key Points

• Bone marrow tests are used to check whether your bone marrow is healthy. These tests show if 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 the doctor wants to look the bone marrow structure.
• Bone marrow tests take about 20 minutes. 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 producing enough healthy blood cells. If it's not, the results can tell your doctor which cells are unhealthy and why.
• Your doctor combines information from your bone marrow test(s) with information from a physical exam, blood tests, and other tests such as imaging scans and x rays. This information helps your doctor diagnose your condition and plan treatment.
• Bleeding and infection are the two most common complications, but they're rare. In some cases, these tests aren't safe for people with certain bleeding disorders (like hemophilia). Your doctor can tell you whether bone marrow tests are safe for you.