A wound on the leg or ankle caused by abnormal or damaged veins. Venous ulcers are due to abnormal vein function. People may inherit a tendency for abnormal veins. Common causes of damaged veins include blood clots, injury, ageing and obesity. Symptoms include swelling, aching and tiredness in the legs. Usually, a red, irritated skin rash develops into an open wound. Treatment includes leg elevation, compression and wound care. Sometimes surgery is required.