| Non-immune causes |
| Hereditary |
| Enzyme deficiencies (eg, deficiencies of G6PD, pyruvate kinase, glucose-phosphate isomerase, 5' nucleotidase) |
| Hemoglobinopathies (eg, sickle cell disease, thalassemias, unstable hemoglobins) |
| Membrane defects (eg, hereditary spherocytosis, hereditary elliptocytosis, hereditary stomatocytosis) |
| Acquired |
| Liver disease |
| Hypersplenism |
| Infections (eg, Bartonella, Babesia, malaria, clostridial sepsis) |
| Oxidant agents (eg, dapsone, nitrites, aniline dyes) |
| Toxins (eg, lead, copper, snake and spider bites) |
| Infusion of a hypotonic solution |
| Microangiopathic hemolytic anemia (eg, TTP, HUS, aortic stenosis, prosthetic valve leak) |
| Immune causes |
| Warm autoimmune hemolytic anemia |
| Drug-induced immune hemolysis |
| Transfusion reactions (eg, ABO incompatibility, alloantibodies) |
| Paroxysmal cold hemoglobinuria |
| Paroxysmal nocturnal hemoglobinuria |
| Cold agglutinin disease |
| Intravenous infusion of IVIG or anti-RhD immune globulin |
