Definition of Secondary aplastic anemia:

Secondary aplastic anemia is a failure of the bone marrow to make enough blood cells. All blood cell types are affected.

Causes, incidence, and risk factors:

Secondary aplastic anemia is caused by injury to blood stem cells. Normal blood stem cells divide and turn into all blood cell types, mainly white blood cells, red blood cells, and platelets. When blood stem cells are injured, there is a reduction in all blood cell types.

This condition can be caused by:

• Certain drugs
• Chemotherapy
• Disorders present at birth (congenital disorders)
• Drug therapy to suppress the immune system
• Pregnancy
• Radiation therapy
• Toxins such as benzene or arsenic

When the cause is unknown, it is referred to as idiopathic aplastic anemia. In about half of all cases, no cause can be found.

The disease may be acute or chronic.