[Venous and lymphatic reasons for edema--the swollen leg from the angiologist's point of view].
Peripheral edema develop as a consequence of imbalance in the processes of filtration, resorption and lymphatic transport in the capillary bed. Venous hypertension and impaired lymphatic function belong to the most important underlying pathomechanisms. Chronic venous insufficiency as a result of valve degeneration as well as venous obstruction in acute deep thrombosis lead to venous hypertension and to an increase of filtration pressure. As venous diseases are frequent, they are one of the most reasons for a swollen leg in clinical everyday life. Primary and secondary disturbances of the lymphatic system are another important reason for interstitial liquid retention. Although there are about 140 millions of people suffering from lymphedema worldwide, the disease is still underdiagnosed.