Our veins pump thousands of liters of blood to the heart every day. The muscles of the body help to transport the blood back to the heart. The blood is transported further through tension and relaxation. Valves, called venous valves, prevent blood from flowing backwards in the veins. However, if the valves are leaky, the veins underneath dilate and "varicose veins" develop. Around 61% of women and 55% of men are affected. Varicose veins are only a cosmetic problem, but above all a serious medical problem. Venous vessels must be adequately supplied with nutrients in order to be elastic and resistant.