Chronic venous insufficiency is a condition in which the veins have problems sending blood from the legs back to the heart due to damaged valves that allow blood to leak backward. This condition causes blood to pool in the leg veins, producing swelling in the ankles, aching and fatigue in the legs and venous ulcers on the legs and feet. The valve damage that causes chronic venous insufficiency may occur due to aging and/or prolonged sitting or standing in one place, or it can be associated with the formation of a blood clot in the deep veins of the legs, which is called deep vein thrombosis. Patients who are especially tall, obese, pregnant or have a family history of chronic venous insufficiency have an elevated risk of developing it. Treatment may involve wearing compression stockings, avoiding sitting or standing for long periods, a weight-loss program and exercise. When such conservative measures have been exhausted, additional treatments may be considered including sclerotherapy, ablation procedures, microphlebectomy (vein stripping), vein bypass and angioplasty and stenting procedures.