Vein disease occurs when veins have trouble carrying blood from your body back to your heart. To over come the force of gravity, inside the veins are one way valves which open to allow blood flow to the heart, and close to prevent “reflux” of blood back to the body. Good valves close tightly, while unhealthy valves fail to close completely. If you have unhealthy valves, backflow can result in dilation and blood pooling inside the vein, causing a variety of vein complications and a medical condition called venous insufficiency. Venous insufficiency can lead to the development of small spider veins on the skin’s surface or varicose veins which are large and distended. Left untreated this can lead to skin changes, ulcers and clotting.