Varicose Vein Causes and Risk Factors

Veins, which carry blood back to the heart from the body and its extremities, contain valves that prevent blood from flowing in the opposite direction. If the valves become weak or damaged, blood can flow backwards and pool in the veins, causing pressure that stretches and enlarges them, eventually resulting in the visible signs of varicose veins in the form of twisted, bulging, or discolored areas on the skin.