Disseminated Intravascular Coagulation (DIC)
Thrombotic Thrombocytopenic Purpura (TTP)
Hemolytic Uremic Syndrome (HUS)
HELLP syndrome
Heparin-Induced Thrombocytopenia (HIT)
Hereditary spherocytosis
Paroxysmal nocturnal hemoglobinuria (PNH)
Malignant hypertension
Scleroderma
Antiphospholipid Syndrome (APS)
Other medical causes: malignancy, renal allograft rejection, vasculitides like polyarteritis nodosa and Wegener's granulomatosis
Drugs: chemotherapy; Clopidogrel (Plavix) associated with TTP
Nonvascular causes: prosthetic valve (more common with mechanical, more common at aortic valve), LVAD, TIPS, coil embolization, patched AV shunt, AVM
Microangiopathic hemolytic anemia
Disseminated Intravascular Coagulation 
Autoimmune hemolytic anemia
Thrombotic Thrombocytopenic Purpura 
Polycythemia vera
Hemolytic Uremic Syndrome 
Aplastic anemia
HELLP syndrome