Causes of secondary aplastic anemia include chemotherapy , drug therapy to suppress the immune system, radiation therapy , toxins such as benzene or arsenic, drugs, pregnancy , congenital disorders, infectious hepatitis , and systemic lupus erythematosus . The cause may be unknown, and is then referred to as idiopathic aplastic anemia .
Symptoms arise as a consequence of bone-marrow failure.
The disease may be acute or chronic and is always progressive. The risk factors are unknown. The incidence is 4 out of 100,000 people. Avod toxins such as benzene or arsenic if possible. A CBC shows low hematocrit and hemoglobin levels.