What causes leg ulcers?
Venous insufficiency refers to improper functioning of the one-way valves in the veins. Veins drain blood from the feet and lower legs uphill to the heart. Two mechanisms assist this uphill flow, the calf muscle pump which pushes blood towards the heart during exercise, and the one-way valves which prevent the flow of blood back downhill. There may be reflux through the valves, obstruction of the veins and/or impaired calf pumping action result in pooling of blood around the lower part of the leg to just below the ankle. The increased venous pressure causes fibrin deposits around the capillaries, which then act as a barrier to the flow of oxygen and nutrients to muscle and skin tissue. The death of tissue cells leads to the ulceration. Arterial insufficiency refers to poor blood circulation to the lower leg and foot and is most often due to atherosclerosis. In atherosclerosis the arteries become narrowed from deposits of fatty substances in the arterial vessel walls, often due to high
