Oedema of the lower extremities is a very frequent symptom in human pathology. It results from the excessive exudation of liquid from the capillary vessels into the extravascular space. In the pathomechanism of the development of oedema an increase in hydrostatic pressure on the one hand, and a decrease of oncotic pressure on the other, play a crucial role. Hydrostatic pressure conveys the fluid outside the vessels. The forces of colloid osmotic pressure act in the opposite way and retain the fluid in the lumen of the vessel. The degree of permeability of the capillary vessels is also of great importance in order to retain the fluid in the lumen of the vessel. Pathologically increased permeability of capillaries plays a decisive role in the development of in-flammatory and allergic oedema. The most frequent causes of oedema of the lower extremities are vascular system diseases and heart failure. A special type of edema is lymphatic oedema which, con-trary to other types of oedema, covers also the toes. Oedema in pregnancy poisoning always requires interdisciplinary care and intensified treatment. An accurate history taking and detailed clinical tests enable the differentiation between renal oe-dema and hormonal oedema, and oedema present in hepatic diseases. It should be remembered that some drugs may also cause the development of oedema in the region of the ankles. Patients with oedema of the lower extremities often constitute a serious diagnostic problem and frequently require various research procedures. Nevertheless, in 25-30% of patients it is not possible to establish the cause of oedema described as idiomatic