Sclerotherapy is a medical procedure used to treat blood vessels or blood vessel malformations (vascular malformations) and also those of the lymphatic system. Sclerotherapy involves an injection of a solution, sclerosant directly into the vein which makes them shrink. The solution irritates the lining of the blood vessel, causing it to swell and stick together, and the blood to clot. Over time, the vessel turns into scar tissue that fades from view. In adults, sclerotherapy is often used to treat varicose veins and hemorrhoids.

Sclerotherapy is the “gold standard” and is preferred over laser for eliminating large spider veins (telangiectasiae) and very small varicose leg veins.