The causes of leg ulcers are venous disease and arterial disease, states WebMD. Underlying conditions such as rheumatoid arthritis and diabetes can also cause leg ulcers.
Leg ulcers are open sores that develop on broken skin as a result of air or bacteria entering the underlying tissues, according to WebMD. They mostly occur on the inside of the leg, above the ankle. The broken skin can be the result of an injury or an underlying disease that affects the leg veins. When the injured skin fails to heal quickly, the injury can enlarge and form an ulcer.
Venous disease causes most leg ulcers, states WebMD. This disease occurs when the veins malfunction due to faulty valves. Faulty veins hinder the flow of blood up toward the heart during blood circulation. As a result, the blood in the veins flows back into the legs, escalating pressure in the veins. The pressure in the veins can cause thinning skin and inflammation, which create chances of venous ulcers.
Unlike venous disease, arterial disease occurs when one or more of the leg arteries becomes blocked, causing poor blood circulation, explains WebMD. The blockage prevents the flow of blood to underlying tissues, leading to arterial leg ulcers.