Immune hemolytic anemia is a condition in which there is a reduced blood cell count due to the premature destruction of red blood cells by the immune system.

Immune hemolytic anemia occurs when antibodies form against the body's own red blood cells. The antibodies destroy the blood cells because the immune system mistakenly recognizes these blood cells as foreign material within the body.

The antibodies may be caused by:

• Complication of another disease
• Past blood transfusions
• Pregnancy (if the baby's blood type is different from the mother's)
• Reaction to certain medications
• Reaction to certain infections

If the cause of antibody formation is a disease or medication, it is referred to as secondary immune hemolytic anemia. Idiopathic autoimmune hemolytic anemia accounts for one-half of all immune hemolytic anemias.

Risk factors are related to the causes.