?? Venous disease, disorders of the veins, ??? the blood vessels that return blood to the heart ??? includes conditions such as varicose veins; chronic venous insufficiency, a serious disorder caused by defective valves in the veins; and deep vein thrombosis (blood clots). ?? Stroke is usually caused by a build up of arteriosclerosis plaque in the carotid arteries ??? the blood vessels that supply