Premature destruction of RBCs, either intravascularly or extravascularly, leading to a shortened red cell survival time. The premature destruction can be caused by intrinsic factors (defects within the RBC itself) or extrinsic factors (factors outside the RBC leads to premature destruction).


Incidence depends on the cause of hemolysis.


Table 1 Common mechanisms of hemolysis
Acquired (extrinsic) disordersHereditary (intrinsic) disorders
Drug inducedRBC membrane defects
Immune mediatedRBC enzyme defects

Risk Factors

  • Acquired (extrinsic): ABO and/or Rh incapability is a risk factor in the newborn period.
  • Hereditary (intrinsic): Although many hereditary disorders are autosomal dominant, 20% of these patients represent new spontaneous mutations and have no affected family members.

General Prevention

  • Acquired (extrinsic): Most causes of acquired, non–transfusion-related hemolytic disease are not preventable.
  • Hereditary (intrinsic): Although there is no way to prevent hereditary forms of hemolysis, newborn screening can help identify and allow proper management of some of these conditions. Patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency should be counseled to avoid triggers such as fava beans, broad beans, and mothballs.

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