Varicose veins (varicosis) are one of the most common diseases in humans and are known as a “common disease.” According to the Basel study, 56% of the examined individuals showed signs of varicose veins, with 12% of these cases requiring medical treatment.
Varicose veins affect the superficial veins in the legs that are located in the subcutaneous fatty tissue. These superficial veins differ from the deep venous system, which runs deeper in the body parallel to arteries and nerves. A superficially located, sack-like, and twisted vein is referred to as varicose.
There are two main types of varicose veins: primary and secondary varicosis.
- Primary varicosis is caused by a genetic weakness of the veins, which is exacerbated by factors such as obesity, pregnancy, long periods of standing, or right heart failure. A genetic predisposition is also considered a cause.
- Secondary varicosis results from the obstruction of the deep leg veins, for example, due to a venous thrombosis, which leads to impaired blood flow, increased venous pressure, and venous valve insufficiency.
In healthy individuals, blood is normally transported from the legs back to the heart through muscle contractions, with venous valves preventing the blood from flowing back due to gravity. In patients with varicose veins, these venous valves in the superficial veins do not close properly, allowing blood to flow back from the superficial veins into the deep venous system (referred to as insufficiency). This leads to volume overload and expansion of the deep veins, resulting in the deep venous valves becoming inefficient. This causes increased pressure in the venous system, leading to the formation of ulcers (referred to as venous ulcers).