As we already know, the circulation of the blood consists of two systems: arteries and veins, and these two systems are connected by means of blood vessels. Arteries carry oxygen-rich blood as far as the legs. Veins, on the other hand, return oxygen-poor blood carrying harmful substances to the heart, despite the phenomenon of gravity.

The cardiac valves, which act like any other valves, prevent the backflow of blood into the vessels. However, if these valves are faulty, oxygen-poor blood circulates in the wrong direction, i.e. back towards the legs. The resulting chronic overpressure in the legs, and in particular in the skin, causes numerous complications (pruritus, skin lesions, venous thromboses, eschars).