Virchow's triad or the triad of Virchow

The triad consists of three components:

	Modern	Notes
Phenomena of interrupted blood-flow	Stasis	The first category, alterations in normal blood flow, refers to several situations. These include venous stasis, long surgical operations, prolonged immobility (as on a long plane or car ride, bed bound during hospitalization), and varicose veins. The equivalence of Virchow's version and the modern version has been disputed.
Phenomena associated with irritation of the vessel and its vicinity	Endothelial injuryor vessel wall injury	The second category, injuries and/or trauma to endothelium includes vessel piercings and damages arising from shear stress orhypertension. This category is ruled by surface phenomena and contact with procoagulant ..
Phenomena of blood-coagulation	Hypercoagulability	The last category, alterations in the constitution of blood, has numerous possible risk factors such as hyperviscosity, coagulation factor V Leiden mutation, coagulation factor II G2021A mutation, deficiency of antithrombin III, protein C or S deficiency, nephrotic syndrome, changes after severe trauma or burn, cancer, late pregnancy and delivery, race, advanced age, cigarette smoking, hormonal contraceptives, and obesity. All of these risk factors can cause the situation called hypercoagulability (excessively easy clotting of blood).