Too few
Thrombocytopenia
Nonfunctional
Aspirin
Von Willebrand disease
Thrombocytopenia
Aspirin
Von Willebrand disease
Acquired (Drug Related)
Warfarin (Coumadin)
Unfractionated heparin
Low molecular weight heparin (i.e. enoxaparin (Lovenox), dalteparin)
Factor Xa Inhibitors (e.g. rivaroxaban, apixaban, fondaparinux, edoxaban)
Direct thrombin inhibitors (e.g. dabigatran, argatroban, bivalirudin)
Illness induced
Vitamin K deficiency
Disseminated Intravascular Coagulation (DIC)
Liver disease induced coagulopathy
Uremic bleeding syndrome
Genetic<unk> 
Factor VIII inhibitor
Lupus anticoagulant
Warfarin (Coumadin)
Unfractionated heparin
Low molecular weight heparin (i.e. enoxaparin (Lovenox), dalteparin)
Factor Xa Inhibitors (e.g. rivaroxaban, apixaban, fondaparinux, edoxaban)
Direct thrombin inhibitors (e.g. dabigatran, argatroban, bivalirudin)
Vitamin K deficiency
Disseminated Intravascular Coagulation (DIC)
Liver disease induced coagulopathy
Uremic bleeding syndrome<unk> 
Factor VIII inhibitor
Lupus anticoagulant
Hemophilia
Too few
Von Willebrand disease
Thrombocytopenia
Factor V Leiden
Nonfunctional
Hereditary hemorrhagic telangiectasia
Aspirin