Pneumothorax refers to pleural injury due to trauma or lung disease, etc. Air enters the pleural cavity, resulting in accumulation of gas in the pleural cavity, which can cause clinical symptoms such as coughing, chest pain, chest tightness and dyspnea. The treatment of pneumothorax lies in pumping and decompression, promoting lung reopening, eliminating the cause of the disease, and reducing recurrence. Therefore, for a large number of pneumothorax, serious dyspnea with the need for thoracocentesis and pumping or closed drainage of the thoracic cavity, and the amount of gas is less than 20% of the thoracic cavity, the patient can be observed with oxygen. Common causes and classification of pneumothorax: 1. Open pneumothorax caused by penetrating chest wall injury requires wound closure and closed chest drainage. 2. Spontaneous pneumothorax can be categorized into three types: closed pneumothorax, open pneumothorax, and tension pneumothorax according to the rupture of the pleura of the dirty layer. Tension pneumothorax has the possibility of sudden death, and requires urgent suction and decompression. 3. According to whether there is primary lung disease, spontaneous pneumothorax can be divided into primary pneumothorax and secondary pneumothorax: primary pneumothorax is mostly seen in tall and thin young people, and it is formed by rupture of subpleural alveoli; secondary pneumothorax is mostly seen in chronic obstructive pulmonary disease, lung infection, tuberculosis and lung cancer. 4. Medical pneumothorax: percutaneous lung puncture biopsy, central venous catheterization, thoracocentesis, etc. can cause medical pneumothorax. Patients with pneumothorax are recommended to go to the hospital for further diagnosis and treatment.