I. Injury of vascular endothelial cells |
Mechanical (atherosclerosis), chemical (medication), or biologic (endotoxin) |
II. Increase in platelet amount and activity |
Thrombocytosis, injuries caused by mechanical, chemical, or immune factors |
III. Increased blood coagulation |
Pregnancy, advanced age, trauma, or tumor |
IV. Decreased anticoagulant activity |
Decreased antithrombin, protein C, S, or vitamin B12 deficiency, hyperhomocysteinemia |
V. Decrease of fibrinolytic activities |
Abnormality of plasminogen activator release or increased inhibition |
VI. Abnormality of hemorheology |
Hyperfibrinogenemia, hyperlipidemia, dehydration, or polycythemia |