Varicose veins and chronic venous insufficiency are forms of primary venous disease, which occurs as a result of focal or diffuse structural weakening of the vein wall. The exact nature and cause are not completely understood. Valvular incompetence in the superficial veins can occur due to disruption by thrombotic events, be congenitally absent, atretic or dysfunctional over time.
The 2 major veins of the superficial system namely the Great Saphenous and Short Saphenous (GSV and SSV).