Varicose veins, reticular veins, and spider veins are permanent dilations of small superficial blood vessels on the legs. Heredity may be the main reason leg veins develop but hormones, trauma, high impact exercise, and long periods of standing are contributing factors. Advances in laser technology are improving so that leg veins can safely be removed using laser light without leaving a scar. When the dilated blood vessels are hit by the laser light they are sealed so the blood can no longer flow into the vessel. In many cases sclerotherapy is a less expensive and better option for treating varicose veins than the use of a laser.