Pneumothorax

The surface of the lung is covered by a membrane called the visceral pleura, and the inner layer of the chest wall is also covered by a membrane called the parietal pleura. The sealed space between these two layers is known as the pleural cavity. Under normal conditions, the pressure within the pleural cavity is lower than atmospheric pressure, which not only keeps the lungs expanded but also facilitates the return of venous blood and lymphatic fluid. Pneumothorax refers to the accumulation of gas in the pleural cavity, caused by chest trauma, lung diseases, mechanical ventilation, or other factors. This gas accumulation impairs lung expansion and leads to lung collapse. The incidence of this condition is higher in males than in females. The main symptoms include chest pain and dyspnea.