What is a venous skin ulcer?

A skin ulcer is a type of wound that develops on the skin. A venous skin ulcer is a shallow wound that occurs when the leg veins don't return blood back toward the heart the way they should. This is called venous insufficiency. See a picture of abnormal blood flow caused by venous insufficiency .

These ulcers usually form on the sides of the lower leg, above the ankle and below the calf. See a picture of areas affected by venous skin ulcers .

Venous skin ulcers are slow to heal and often come back if you don't take steps to prevent them.

A venous skin ulcer is also called a stasis leg ulcer.

What causes venous skin ulcers?

Venous skin ulcers are caused by poor blood circulation from the legs, such as from venous insufficiency. Your veins have one-way valves that keep blood flowing toward the heart. In venous insufficiency, the valves are damaged, and blood backs up and pools in the vein. The blood may leak out of the vein and into the surrounding tissue. This can lead to a breakdown of the tissue and an ulcer.

Veins that become blocked also may cause blood to pool, leading to these ulcers.

Some things can increase your risk of venous skin ulcers. These include:

• Deep vein thrombosis, in which a blood clot (thrombus) forms in the deep veins of the legs.
• Obesity.
• Smoking.
• Lack of physical activity.
• Work that requires many hours of standing.

There are two other types of skin ulcers that can happen on the lower leg or feet. They are different from venous skin ulcers.

• Arterial skin ulcers are less common than venous skin ulcers. They happen when artery disease is present (sometimes in combination with venous disease). These ulcers tend to be extremely painful. They are usually on the toes and feet.
• Neuropathic skin ulcers are also known as diabetic neuropathic ulcers. They occur in people who have little or no sensation in their feet because of diabetic nerve damage.

What are the symptoms?

The first sign of a venous skin ulcer is skin that turns dark red or purple over the area where the blood is leaking out of the vein. The skin also may become thick, dry, and itchy.

Without treatment, an ulcer may form. The ulcer may be painful. You also may have swollen and achy legs.

If the wound becomes infected, the infection may cause an odor, and pus may drain from the wound. The area around the wound also may be more tender and red.

Call your doctor when you first notice the signs of a venous skin ulcer, because you may be able to prevent the ulcer from forming. If an ulcer has formed, get treatment right away, because new and smaller ulcers tend to heal faster than larger ones.

How are venous skin ulcers diagnosed?