Threedimensional illustration of a varicose vein surrounded by muscle fibers. Varices are widened, sidled, superficial veins. Due to the widening and the resulting impossibility of closing the valves, the transport of venous blood to the heart is impaired, so that blood swashes back. The reason for varices can be a congenital weakness of connective tissue that causes a functional damage of the venous valves (primary varicose veins), then again the reason can be a hindrance of drainage in the profound venous system, due to e.g. a tumor or thrombosis (secondary varicous veins). Factors like a job with a lot of standing, lack of excercise, pregnancy and overweight promote their development. Typical symptoms are a feeling of heaviness in the legs, nocturnal leg cramps, swelling of the legs (especially in the ankle area) and discoloring of the skin. Diagnostic methods include an exhaustive physical examination, ultrasonic testing (sonography) and an X-ray examination of the leg veins (phlebography). Therapeutic options are compression hoseries or bandages, shrinking down the vessel or a complete removal of the varicous veins (vein stripping).