Venous insufficiency may also manifest itself as leg swelling, skin discoloration, and eventual scarring of the skin and fat to the underlying muscle (stasis dermatitis or lipodermatosclerosis). Lipodermatosclerosis is a significant risk factor in the development of recurrent skin infections and a precursor to venous ulceration. Venous ulcers are typically the result of incidental skin trauma such as a bug bite, dishwasher door, skin biopsy or other event which causes and opening in the diseased skin. These wounds often have difficulty healing because of the unhealthy nature of the skin and extra fluid in the tissues which impairs the delivery of oxygen to the wounds. Small tears and simple wounds may fester for months and gradually grow larger. Early evaluation of the venous system is important in establishing the underlying cause of these wounds and in expediting the most effective treatment plan. Leg wounds are usually related to one of three causes; venous disease, arterial disease or nerve damage (neuropathy). Non-healing leg wounds should be evaluated early in their course to determine which of these causes are most likely responsible. Wounds need oxygen delivery, granulation and contraction. Venous insufficiency impairs all 3 of these processes through the accumulation of fluid in the soft tissues as a result of leaky valves causing high venous pressure in the legs. Once the culprit veins are treated, edema resolves and oxygen diffusion improves, leading to healthy granulation tissue and finally wound contraction or closure.