What is aplastic anemia?

Answer 1

Aplastic anemia is a condition where bone marrow does not produce sufficient new cells to replenish blood cells. The term 'aplastic' means the marrow suffers from an aplasia that renders it unable to function properly. Anemia is the condition of having fewer red blood cells than normal, or fewer than needed to function properly. Typically, anemia refers to low red blood cell counts, but aplastic anemia patients have lower counts of all three blood cell types: red blood cells, white blood cells, and platelets. copied from wikipedia

Answer 2

Many times the cause is never known. Some factors do increase your risk, such as Radiation and chemotherapy, Exposure to toxic chemicals, Use of certain drugs, Viral infections (hepatitis, Epstein-Barr, cytomegalovirus, parvovirus B19 and HIV), and Pregnancy.