[Pneumothorax].

During traumatic lesions, lung diseases or even spontaneously air can reach the pleural cavity causing a so called pneumothorax. If a valve mechanism develops, the high pressure in the pleural cavity impaires the blood flow to the heart, causing a circulatory insufficiency. This situation can develop very quickly and therefore must be very fast diagnosed and treated because of the life threatening character. Clinical symptoms and findings should be the main stay in the diagnosis. X-ray and CT may provide additional information concerning the cause of the disease. The therapy consists of draining the air by tube suction or by surgical closing of the leak in the pleura. The paper gives some practical information concerning the therapy.