Laser Leg Vein Treatments work by selectively heating vein walls until they collapse. Then over a period of a month, the vein is absorbed by the body. In many cases you will see part of the vein disappear with each pulse. Most clients experience considerable improvement after 2-3 treatments. The skin may have some swelling and redness for a few days, and on rare occasions there may be some bruising. Sun exposure must be limited after treatment.