Chronic venous insufficiency (CVI) occurs when the venous wall and/or valves in the leg veins are not working properly, making it difficult for blood to return to the heart from the legs. CVI causes blood to collect in these veins, which increases pressure in your leg veins. This can lead to swelling and sores on your legs. Listen to vascular surgeon James Herrington, MD, discuss the causes, symptoms and treatments of CVI on Hurley in the Morning.