Pathogenesis of thrombosis

The pathogenesis of thrombosis involves consideration of two processes: atherosclerosis and thrombosis. Atherosclerosis is a prolonged process in which interaction of lipids and the haemostatic system produces focal lesions at sites of turbulence in arteries. These lesions may rupture, precipitating the complication of thrombosis and leading to complete occlusion of the vessel, causing myocardial infarction, stroke, or acute ischaemia. In veins the atherosclerotic process does not occur, and thrombosis is precipitated by immobility often associated with accidental or surgical trauma. The changes in platelets, coagulation, fibrinolytic systems leading to atherosclerosis and thrombi are reviewed. The role of platelets and coagulation changes in these processes are emphasized by the beneficial effects of therapy, both antiplatelet and anticoagulant therapy. Last, the concept of hypercoagulability leading to accelerated arterial disease and the clinical value of laboratory tests used in its detection are considered.