Intrinsic hemolytic anemias are often inherited, such as thalassemia and sickle cell anemia. The bone marrow produces red blood cells which are defective so their lifespan is shorter than normal red blood cells.
Extrinsic hemolytic anemia may also be referred to as autoimmune hemolytic anemia. The bone marrow produces red blood cells which are initially healthy. Some types of extrinsic hemolytic anemia are temporary and never return after treatment. Other types are chronic, which may have times of remission and then relapse. The red blood cells are subsequently destroyed by one of the following:
- The red blood cells get trapped in the spleen
- Taking medications that affect red blood cells
- Various tumors
- Autoimmune disorders
- Leukemia or lymphoma
- Abnormalities of the blood vessel