The most common cause of pneumothorax in adolescents is idiopathic pneumothorax, which can be seen in adolescents who are taller, thinner and longer in body type, and usually have no history of respiratory disease, but there is a lung blister under the pleura, which will form a pneumothorax once it ruptures. Second, it may be caused by trauma, the activities of teenagers are relatively large, prone to all kinds of trauma, once the trauma occurs, it will lead to the fracture of ribs, and may penetrate the pleura, leading to the occurrence of pneumothorax. Third, the stabbing of sharp instruments may also lead to pneumothorax, gunshot wounds or diagnostic medical operations, can also cause pneumothorax. Fourth, secondary pneumothorax, but adolescents are relatively rare, such as chronic bronchitis, bronchial asthma caused by obstructive pulmonary disease, also easy to lead to the occurrence of pneumothorax. Fifth, lung abscess or tuberculosis may also cause pneumothorax in adolescents.