Lasers are used in two different ways to treat varicose and spider veins. Varicose veins are abnormal, bulging veins visible on the surface of the legs. They are caused by venous insufficiency, also called venous reflux, of underlying veins. Endovenous laser ablation (EVLA), also called endovenous laser therapy (EVLT) is a procedure where a fiberoptic catheter is placed in the abnormal vein. The laser energy heats the vein, causing it to close down (coagulate). Local anesthesia using lidocaine is used to numb up the vein prior to ablation. Surface laser therapy uses a narrow laser beam to ablate (destroy) thin spider veins. It works by heating up the blood in the spider vein, which closes the vein. No anesthesia is used. It feels like someone is tapping you with a sharp fingernail, or the snap of a rubber band. Most spider veins are treated with sclerotherapy, as it is more time efficient and can treat a wider size range of veins. In my practice, I reserve surface laser therapy for spider veins that are on the face, or are very small, or when sclerotherapy was not effective.