The arteries supply blood, which carries the oxygen that cells need to live. If arterial circulation is partially or completely blocked, the tissue will begin to die, resulting in a painful wound. Veins carry deoxygenated blood back to the lungs. Veins contain valves that prevent backflow, but when these valves become incompetent, too much blood remains in the tissues. This condition is called congestion.
Venous ulcers are the most common wounds affecting the legs, and are frequently found on the ankles.
They are shallow, not too painful, and may have a weeping discharge. Although venous valves cannot be repaired, the return of blood through the veins can be improved by physical activity and by compression, which can be supplied by compression stockings, dressings, or mechanical pumping devices. Diabetic foot ulcers. Diabetes results in a narrowing of the small arteries, which can cause ulcers. This narrowing cannot be resolved, but can be prevented by careful glucose control.