Chronic venous insufficiency (CVI) is a complex of symptoms occurring on the lower leg, which includes varicose veins, oedema, pigmentation and venous leg ulceration. Most patients have severe complaints, which result in a high medical consumption, mainly due to venous leg ulceration. CVI is caused by a decompensation of the venous system together with reflux in the superficial, deep and/or perforating veins of the lower leg in supine position. The exact pathogenesis of the skin symptoms is still largely unclear. An increased walking venous pressure induces macrocirculatory and microcirculatory changes such as dermal pericapillary fibrin cuffs, leukocyte accumulation and the activation of cytokines. CVI can be treated in several ways: compression therapy, if needs be combined with sclerotherapy or surgery, or with supportive medication.