Venous insufficiency is a condition in which the veins do not efficiently return blood from the lower limbs back to the heart. If the valves within the veins malfunction or the calf-muscle pump fails, reflux occurs, veins remain full and the pressure in the veins becomes abnormally high (venous hypertension). Venous hypertension appears to be the common denominator behind the different manifestations of venous disease. It can lead to varicose veins and spider veins, ankle swelling and skin damages. Appropriate diagnostic testing can pinpoint the areas of reflux and assess the calf-muscle pump to formulate an appropriate treatment plan.