Table 2.

Causes of intravascular hemolysis

Complement fixation (eg)

Paroxysmal nocturnal hemoglobinuria

Paroxysmal cold hemoglobinuria

Acute hemolytic transfusion reactions due to mismatched blood

Some autoimmune hemolytic anemias if complement fixation allows terminal complement activation (membrane attack complex formation) on the surface of red blood cells causing lysis

Mechanical trauma (eg)

Cardiac valves

Microthrombi in circulation - DIC, MAHA (TTP, HUS, aHUS)

March hemoglobinuria

Toxic or exogenous factors (eg)

Infections: Babesia, Clostridium, Leptospira, Falciparum malaria

Spider bites

Snake venoms

Copper or zinc toxicity

Hypotonic solutions

aHUS, atypical hemolytic uremic syndrome; DIC, disseminated intravascular coagulation; HUS, hemolytic uremic syndrome; MAHA, microangiopathic hemolytic anemia; TTP, thrombotic thrombocytopenic purpura.