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

Typically, bone marrow tests are performed 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.

The area where your doctor will insert the needle will be numbed. 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 monitor your breathing, heart rate, and blood pressure during the tests.

The area on your body where your doctor inserts 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 in your skin to make inserting the needle into the bone easier. After the test, you may 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 following 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).