Hemolytic anemia is a disorder in which blood cells are prematurelly destructed, and the speed of the distruction is faster than their production by bone marrow. Premature destruction of the blood cells is called hemolysis.
anemia does not occur if the blood cell production by bone marrow can compensate the premature destruction.
There are two categories of hemolytic anemia: intrinsic and extrinsic.
- Intrinsic hemolytic anemia is due to defect inside the blood cells. The blood cells are producted unhealthy, and live shorter than normal, such as G-6-PD deficiency, sickle cell anemia.
- In extrinsic hemolytic anemia, blood cells are produced healthy, but hemolized later by factors outside the blood cells, such as immune response, drug, chemicals. Blood cells are trapped in the spleen, then destroyed.
Hemolytic anemia occurs when the bone marrow is unable to compensate for premature destruction of red blood cells by increasing their production. When the marrow is able to compensate, anemia does not occur.
There are many types of hemolytic anemia, which are classified by the location of the defect. The defect may be in the red blood cell itself (intrinsic factor), or outside the red blood cell (extrinsic factor).
Causes of hemolytic anemia include infection, certain medications, autoimmune disorders, and inherited disorders. Types of hemolytic anemia include:
Sickle-cell anemia
Paroxysmal nocturnal hemoglobinuria
Hemoglobin SC disease
Hemolytic anemia due to G6PD deficiency
Hereditary elliptocytosis
Hereditary spherocytosis
Hereditary ovalocytosis
Idiopathic autoimmune hemolytic anemia
Non-immune hemolytic anemia caused by chemical or physical agents
Secondary immune hemolytic anemia
Thalassemia
