Environmental And Genetic Risk Factors For Venous Thrombosis

The hemostatic system has evolved to maintain blood in a fluid state under physiological conditions, and also to react rapidly to vessel injury by sealing defects with fibrin clots (Kleinschnitz, et al.,2006). The hemostatic system is a complex mosaic composed of five major compon-ents: blood vessels, blood platelets, coagulation factors, coagulation inh-ibitors and fibrinolytic elements (Kemball-Cook, et al.,2005). The balance between the inhibitors of coagulation and the activation of the coagulation factors ensures normal hemostasis, and imbalances can lead to thrombosis or hemorrhage (Crowther and Kelton,2003).Thrombosis is defined as obstructive clot formation. It represents the end product of procoagulant, anticoagulant and fibrinolytic factors. It may occur in arteries and veins. While venous thrombosis is an acute disorder with chronic symptoms, arterial thrombosis is a chronic disease with acute symptoms (Rosendaal,2005).