A venous skin ulcer is a shallow wound caused by venous insufficiency, a condition in which the valves in the blood vessels are damaged and allow some blood to back up in the veins. The slowed circulation causes fluid to seep out of the overfilled veins into surrounding tissues, causing tissue breakdown and ulcers.

Venous skin ulcers, also called stasis leg ulcers, typically develop on either side of the lower leg, above the ankle and below the calf.

The first sign of a skin ulcer is an affected area of skin that turns dark red or purple. It may also become thickened and dry and itchy. Without treatment, an open wound (ulcer) may form. Venous skin ulcers often weep clear fluid and are covered with yellowish film.

The most effective treatment for venous skin ulcers is frequent elevation of the legs above the level of the heart and use of compression stockings during waking hours.