Lower extremity venous insufficiency (valve failure) is progressive if not treated effectively, the symptoms can progress from pain and swelling to skin discoloration and skin ulceration. The skin discoloration is caused by the deposition of iron in the skin. Red blood cells (which contain iron) are forced outside the vein by a progressive increase in venous pressure as more and more valves within the veins fail (domino effect). The skin may ulcerate if the venous pressure rises high enough to interfere with the nutritional support to the skin. Treatment directed at the high venous pressures will heal the ulcerated skin (endovenous laser ablation).