What Is Bone Marrow Aspiration and Biopsy?

Medically Reviewed by Sabrina Felson, MD on May 28, 2023
3 min read

A bone marrow aspiration and a bone marrow biopsy are different procedures that often are done together. The two procedures together are also referred to as a “bone marrow examination.”

Bone marrow is the spongy tissue inside your bigger bones that produces red blood cells, white blood cells, and platelets.

Using a needle, the aspiration draws out a sample of the liquid portion of your bone marrow. The biopsy -- also done with a needle -- removes a small, more solid part of the bone marrow.

The tissue is often taken from the back of your hip bone.

Your doctor may have ordered them for one or more of a number of reasons. Among other things, they may want to:

  • Diagnose a disease or ailment that involves the bone marrow or blood cells
  • Figure out the stage of a disease
  • Determine the success of a disease treatment
  • Check your iron levels
  • Study a fever when the cause isn’t known

There’s nothing specific you need to do before the tests, but it is important to share some info with your doctor. You should tell them if you are allergic or sensitive to:

  • Chlorhexidine, which is used in disinfectants
  • Local anesthetics (drugs used to numb areas of your body to prevent feeling pain)
  • Latex (a type of rubber)
  • Adhesives, like tape

Also, if you take drugs to treat or prevent blood clots -- or to prevent a heart attack or stroke -- you’ll need to talk to your doctor well before you have the tests to find out when to stop taking them.

Most likely you will lie on your stomach, face down, or on your side while having the tests done. The bone marrow samples will be taken from the back of your hip bone. Here, in order, is what usually happens during the procedures:

  1. Medical staffers check your blood pressure, heart rate, and body temperature to ensure they’re OK.
  2. If you’ve asked for a sedative in advance, you’ll get it several minutes before the first procedure.
  3. A medical staffer will use a disinfectant to clean your skin where the needle will go.
  4. You’ll get medicine to help numb the area.
  5. For the aspiration, the doctor will insert a needle into your bone. You may feel some pressure. Then they’ll take a small liquid amount of bone marrow through the needle. You may feel some brief pain, or a tugging feeling going down your leg, as the marrow is removed.
  6. For the biopsy, a slightly larger needle will be used. This needle goes to the same place as the one before, and it’ll remove a small core of your marrow. You also might feel some pressure during this procedure.
  7. After both procedures are completed, a small bandage will be placed on the site where the needles went.

The two procedures together usually take about 10 minutes, and the entire process lasts about 30 minutes.

Sometimes you will have had other tests first whose results were abnormal, which led your doctor to order the bone marrow aspiration and biopsy. These tests include:

Right after the procedures, you might feel:

  • Lightheaded for a few minutes
  • Briefly numb in your leg or foot on the side where you had the procedure
  • Sore where the needles entered your skin

After you get home from the procedures:

  • Don’t take aspirin or products that contain aspirin for 24 hours.
  • Don’t take a bath or shower for at least 24 hours.
  • Do talk to your doctor about when to restart any blood thinners.
  • Do keep your bandage on for 24 hours.
  • Do apply pressure on the needle site if it bleeds.

Your bone marrow samples will be sent to a lab for a specialist to look at. Your doctor could get your results in as little as a few days, but it could take longer. The information from the lab will help your doctor:

  • Rule out or confirm a diagnosis
  • Figure out how advanced a disease is
  • Decide how well a treatment is working