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What Are Bone Marrow Tests?

Bone marrow tests check whether your bone marrow is healthy. These tests also show whether your bone marrow is making normal amounts of blood cells.

Bone marrow is a 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 carry oxygen throughout your body.
  • White blood cells fight infections.
  • Platelets (PLATE-lets) stop bleeding.

Another type of stem cell, called an embryonic (em-bre-ON-ik) stem cell, can develop into any type of cell in the body. These cells aren't found in bone marrow.


Doctors use bone marrow tests to diagnose blood and bone marrow diseases and conditions, including:

  • Conditions in which a person produces too few or too many of certain types of blood cells
  • Problems with the structure of red blood cells
  • Bone marrow disorders, such as myelofibrosis (MI-eh-lo-fi-BRO-sis)
  • Some cancers, such as leukemia (lu-KE-me-ah)

Bone marrow tests also help doctors figure out how severe cancer is and how much it has spread in the body. The tests also are used to diagnose fevers and infections.

The two bone marrow tests are aspiration (as-pih-RA-shun) and biopsy.

Bone marrow aspiration usually is done first. For this test, your doctor removes a small sample of fluid bone marrow through a needle. He or she may have some idea of what the problem is, and the sample gives him or her useful information about the cells in the marrow.

A bone marrow biopsy is the followup test. It's done to provide more information about your cells. Also, a biopsy is done if your doctor wants to examine the bone marrow structure itself. For this test, your doctor uses a needle to remove a sample of bone marrow tissue.


Bone marrow tests are fairly simple, and they're safe for most people. Complications are rare, but some people may develop bleeding or infections.

Sometimes bone marrow tests aren't safe for people who have certain bleeding disorders, such as hemophilia. Your doctor can tell you whether a bone marrow test is safe for you.

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Bone Marrow Tests Clinical Trials

Clinical trials are research studies that explore whether a medical strategy, treatment, or device is safe and effective for humans. To find clinical trials that are currently underway for Bone Marrow Tests, visit

December 20, 2011 Last Updated Icon

The NHLBI updates Health Topics articles on a biennial cycle based on a thorough review of research findings and new literature. The articles also are updated as needed if important new research is published. The date on each Health Topics article reflects when the content was originally posted or last revised.