Sclerotherapy is a medical procedure used to eliminate spider veins on the legs. Many factors can contribute to spider veins including hereditary, hormone changes, pregnancy, prolonged sitting or standing or weight fluctuations. Sclerotherapy involves an injection of a salt solution directly into the vein. The solution irritates the lining of the blood vessel, causing it to collapse and the blood to be directed elsewhere. Reduction in the appearance of the small veins is noticed in 6 weeks. Often, more than one session is needed. Risk factors of the procedure include areas of hyperpigmentation where the solution is injected, recurrence of veins, or ulceration.