Gas in the lungs is clinically called pneumothorax, and the common causes are pneumothorax due to trauma, spontaneous pneumothorax and medically induced pneumothorax. Traumatic pneumothorax is caused by rupture of the pleura due to trauma, which causes gas to enter the pleural cavity and compress the lung, thus producing a pneumothorax. Spontaneous pneumothorax is commonly caused by the rupture of pulmonary blisters and is common in patients with underlying diseases, such as chronic obstructive pulmonary disease, bronchial asthma, and patients with a lean and tall body type who also tend to develop pneumothorax. Medical pneumothorax refers to the pneumothorax caused during medical operation, such as pneumothorax caused during thoracoscopy. After pneumothorax occurs, patients will have symptoms of cough, chest pain and chest tightness, which can be clearly diagnosed by chest X-ray or chest CT examination. If pneumothorax occurs repeatedly and there is a pulmonary blister in the lung, pulmonary blister removal surgery can be performed.