Sclerotherapy is a procedure used to treat varicose veins and spider veins. It involves injecting a solution, known as a sclerosant, directly into the affected veins. The sclerosant irritates the vein walls, causing them to collapse and eventually fade away. Sclerotherapy is typically performed on an outpatient basis and does not require anesthesia. The procedure is commonly used to improve the appearance of visible veins, reduce associated symptoms like pain and discomfort, and enhance overall leg aesthetics.