Aplastic anemia, or bone marrow aplasia, forms when the body does not produce enough new blood cells. People with aplastic anemia experience a higher risk of infection and uncontrolled bleeding, and they often feel fatigued. Though rare, aplastic anemia may occur suddenly or develop slowly and worsen over time.
While aplastic anemia is not technically a cancer, the therapies used to treat it are similar to cancer treatments for blood-forming cancers such as lymphomas and leukemias. According to the Aplastic Anemia and MDS International Foundation, 75 percent of aplastic anemia cases are idiopathic, or lacking a known cause.