Sclerotherapy is a treatment that involves the injection of a chemical solution into blood vessels, usually spider veins or varicose veins on the legs. Sclerotherapy is most commonly used for the treatment of unwanted, visible spider veins and superficial (surface) varicose veins.

Sclerotherapy irritates the vessel walls, making them stick together. This leads to fibrosis, or scarring, of the blood vessel. The vessel then becomes unable to carry blood and starts to shrink, making it less visible under the skin. Eventually the blood vessel should disappear altogether.

Spider veins

Spider veins (thread veins) are tiny red or blue veins that can appear anywhere on the body but occur most commonly on the legs. Sclerotherapy is often used to treat spider veins on the legs.

Varicose veins

Varicose veins are generally larger veins that can be raised above the skin’s surface. Varicose veins can sometimes cause aching legs and swelling of the ankles. They can also be associated with burning, stinging, throbbing, restless legs and leg cramps.

Not all varicose veins are suitable for sclerotherapy — if the varicose veins are large or if the valves in the veins are very leaky, surgery may be a better option than sclerotherapy. Your doctor may suggest an ultrasound to see whether your veins are suitable for sclerotherapy.