Sclerotherapy is the "gold standard" and is preferred over laser for eliminating large spider veins (telangiectasiae) and smaller varicose leg veins. Unlike a laser, the sclerosing solution additionally closes the "feeder veins" under the skin that are causing the spider veins to form, thereby making a recurrence of the spider veins in the treated area less likely. Multiple injections of dilute sclerosant are injected into the abnormal surface veins of the involved leg. The patient's leg is then compressed with either stockings or bandages that they wear usually for one week after treatment. Patients are also encouraged to walk regularly during that time. It is common practice for the patient to require at least two treatment sessions separated by several weeks to significantly improve the appearance of their leg veins.