A venous leg ulcer describes an open sore that fails to heal, usually located on the lower portion of the leg. Venous leg ulcers usually appear red and may produce a green or yellow discharge especially when they become infected. The skin surrounding the ulcer usually swells, appears shiny and tight and often feels warm or hot to the touch. The Cleveland Clinic reports that venous leg ulcers account for 90 percent of all leg ulcers. Conditions that affect the flow of blood in the veins of the legs can cause venous leg ulcers.
Venous Insufficiency
Venous insufficiency describes a condition of impaired return blood flow from the legs to the heart. Chronic venous insufficiency affects approximately 5 percent of the population in the U.S., according to the Merck Manual. In order for blood to flow from the legs to the heart, the veins contain a series of valves to direct the blood upward. Contraction of the calf muscle helps to keep the blood flowing up the legs. Venous insufficiency occurs when the muscles fail to contract or when the valves become damaged.
Chronic venous insufficiency causes feelings of fullness, heaviness, aching, cramps or pain in the legs. The symptoms often worsen when standing or walking, as described by the Merck Manual. In addition the lack of blood flow in the lower legs can lead to stasis dermatitis---inflammation of the skin in the legs that can lead to the formation of ulcers.
Venous Hypertension
Venous hypertension, high blood pressure in the lower portion of the legs, affects one to two percent of the United States population, according to Surgical-tutor.org. Conditions that inhibit the flow of blood through the veins in the legs, such as damage to the valves in the veins or an obstruction can cause fluid to accumulate in the lower leg leading to venous hypertension. Venous hypertension causes inflammation of the tissue in the leg and a decrease in the amount of oxygen reaching the cells in the leg, a condition known as hypoxia. These effects of the hypertension lead to the formation of venous ulcers.
Inflammatory Diseases
Inflammatory diseases activate the immune cells in the body leading to an increased number of leukocytes---white blood cells. The white blood cells accumulate in areas of the body to fight the disease. When excess white blood cells build-up in the lower legs, they can obstruct the veins increasing the blood pressure in the lower legs resulting in a venous leg ulcer. Several types of inflammatory diseases can cause venous leg ulcers including lupus, scleroderma and rheumatological conditions, reports the Cleveland Clinic.
