Risk Factors for Venous Thrombotic Disease

Introduction Venous thrombosis occurs in about 1 per 1,000 individuals per year.1,2 It usually affects the deep veins of the leg, but may occur in other sites, such as the upper extremities, cerebral sinus, liver and portal veins, or retinal veins. It also may occur in the superficial veins, usually in the leg. The predilection of thrombosis occurring in the leg is the result of the upright position of man, with the resulting slow...