• Normocytic anemia
• Anemia, general approach

Coombs positive (immune)

• Autoimmune, drugs, infection, lymphoproliferative disease, Rh or ABO incompatibility

Coombs negative

• Intrinsic red cell disease
  • Abnormal hemoglobin: sickle cell disease, thalassemia, methemoglobinemia
  • Membrane defect: hereditary spherocytosis, hereditary elliptocytosis, paroxysmal nocturnal hemoglobinuria
  • Enzyme defect: G6PD deficiency, pyruvate kinase deficiency
• Extrinsic disease
  • Microangiopathic hemolytic anemia: thrombotic thrombocytopenic purpura, hemolytic uremic syndrome, disseminated intravascular coagulation, prosthetic valve hemolysis, metastatic adenocarcinoma, vasculitis, malignant hypertension, HELLP syndrome
  • Splenic sequestration
  • Infection: malaria, Clostridium, Borrelia
  • Burns