People develop spider veins and varicose veins for a number of different reasons. Regardless of why spider veins appear people are not happy at their arrival. Many people think that they have to live with unsightly spider veins. However, a treatment called sclerotherapy can reduce or completely remove spider veins.Sclerotherapy is a cosmetic procedure that treats the vessels and veins within the body. During sclerotherapy, a special medicine is injected into the veins that causes the unsightly veins to contract. This leads to a diminished appearance of spider veins and varicose veins.Generally, sclerotherapy is not a very painful procedure. Most patients experience only mild discomfort from sclerotherapy treatment. This would include a mild to moderate burning sensation after the injection is made that disappears within in moments. However, it is not uncommon for patients to feel tenderness in the legs for a day or two following the procedure.After a patient has sclerotherapy it may take an entire month to notice an improvement in the appearance of spider veins. In fact, most patients have repeat sclerotherapy treatments to achieve their desired results. On average patients will have sclerotherapy two to four times.Sclerotherapy is one of the most effective ways to reduce the appearance of spider veins. The treatment has a 95 percent success rate. However, about 5 percent of the people who seek sclerotherapy to reduce spider veins will see little to no results. In these cases patients must seek alternative methods for spider vein and varicose vein removal.