Chronic venous insufficiency is a cause of leaking veins in the leg, reports MedlinePlus. It is a disorder that prevents the veins from adequately sending blood back to the heart after traveling to the legs. Chronic venous insufficiency occurs due to weakened vein walls and damaged valves in the veins, which in return causes the veins to remain full of blood. Incompetent valves in the veins or a previous blood clot in the legs also cause venous insufficiency.
Chronic venous insufficiency commonly occurs in people with deep vein thrombosis, tumors of the pelvis and vascular malformations, according to the Cleveland Clinic. When it occurs in people with deep vein thrombosis, it is diagnosed as post-thrombotic syndrome. There are numerous risk factors pertaining to chronic venous insufficiency, such as genetics, whether a person tends to sit or stand over long time periods, obesity, pregnancy and a previous diagnosis of deep vein thrombosis, explains MedlinePlus.
Symptoms of chronic venous insufficiency include recent varicose veins, leg pain and leg swelling, states the Cleveland Clinic. An increase of swelling and pressure can occur if the condition is not treated. Untreated, it can cause a burst of the capillaries, potentially resulting in damage and inflammation of the tissues.