Increased risk of thrombosis due to abnormalities of the hemostatic system.

In recent years a number or hereditary or acquired abnormalities of the hemostatic system have been discovered which predispose to thrombosis. The type of this abnormality determines not only whether there is a tendency to venous or arterial thrombosis but also predisposes in some instances to thrombosis at a specific site. Such hemostatic abnormalities may be present in 10-30% of patients with a history of venous thrombosis. The detection of a thrombophilic state has important implications as regards the choice and the duration of antithrombotic treatment.