Bone marrow tests determine whether a person's bone marrow is healthy or not, according to the National Institutes of Health. Bone marrow tests may also determine if bone marrow is producing adequate amounts of blood cells. It is performed by removing small amounts of fluid or tissue from the marrow.
Bone marrow is a tissue that is found inside bones, according to the NIH. It contains stem cells that develop into red blood cells, white blood cells and platelets. Bone marrow tests can also determine if a person has certain cancers or conditions that affect blood cells, including myelofibrosis and leukemia.