Secondary aplastic anemia is a failure of the bone marrow to make enough blood cells. All blood cell types are affected.
Secondary aplastic anemia results from injury to blood stem cells. Normal blood stem cells divide and differentiate into all blood cell types. Thus, when blood stem cells are injured, there is a reduction in red blood cells, white blood cells, and platelets.
This condition can be caused by chemotherapy, drug therapy to suppress the immune system, radiation therapy, toxins such as benzene or arsenic, drugs, pregnancy, and disorders present birth. When the cause is unknown, it is then referred to as idiopathic aplastic anemia.
The disease may be acute or chronic and usually gets worse unless the cause is removed.