2. Secondary pneumothorax: bronchopulmonary diseases penetrate into the chest to form pneumothorax. Such as obstructive pulmonary disease caused by chronic bronchitis, pneumoconiosis and bronchial asthma, pulmonary interstitial fibrosis, alveolar emphysema and bullae caused by partial airway occlusion of honeycomb lung and bronchial lung cancer, purulent pneumonia near pleura, pulmonary abscess and tuberculous cavity, pulmonary mycosis, congenital pulmonary cyst, etc.
3. Idiopathic pneumothorax: it means that there is no history of respiratory diseases, but there may be pulmonary bullae under the pleura. Once ruptured, it is called idiopathic pneumothorax, which is more common in slender young men.
4. Chronic pneumothorax: refers to pneumothorax that has not been completely expanded after 2 months. The reasons are: encapsulated liquid pneumothorax with difficulty in absorption, pneumothorax formed by pleural fistula, pulmonary bullae or congenital bronchial cyst difficult to heal, airway obstruction or atrophy, and the lung is covered with a thick institutionalized capsule to prevent lung recruitment.
5. Traumatic pneumothorax with pleural effusion is called pneumothorax. The incidence of traumatic pneumothorax is about 15% ~ 50% in blunt injury and 30% ~ 87.6% in penetrating injury. In most cases, the air of pneumothorax comes from the puncture of the broken end of rib to the lung (superficial lung rupture, deep bronchiole lung laceration), and it can also be caused by the contusion and laceration of bronchial or lung tissue caused by violence, or by the sudden increase of pressure in the airway. Sharp instrument injury or firearm injury penetrates the chest wall, injuring the lungs, bronchi, trachea or esophagus, and can also cause pneumothorax, mostly hemopneumothorax or empyema. Occasionally, closed or penetrating diaphragmatic rupture is accompanied by gastric rupture, leading to empyema.