Sclerotherapy is performed on spider veins. Spider Veins present no significant health risks but are cosmetically disfiguring. A solution is injected into the vein to irritate the walls so that the vein becomes a scar and does not fill with blood. After treatment, the vein fades away. Frequently, patients require a number of treatment sessions for complete elimination of spider veins. The best results are obtained if the patient wears prescription compression stockings for three to four weeks after each session.