For the examination of subcutaneous emphysema in addition to clinical symptoms examination can be seen in patients due to gas escaping into the subcutaneous tissue of the neck subcutaneous emphysema, neck distension or pressure, but also through further physical examination with X-ray examination, experimental examination, thoracoscopy and other methods. Physical examination: fullness of the affected side of the chest, widening of the intercostal space, weakening of the whistling motion, weakening or disappearance of palpation fibrillation, percussion bullae, and decreasing of the hepatic turbinate boundary in the case of right-sided pneumothorax. In the case of left-sided pneumothorax, the heart murmur boundary narrows or disappears, the auscultatory whistling sound weakens or disappears, and the trachea and heart shift to the healthy side. When a small amount of left-sided pneumothorax or mediastinal emphysema is present, a distant heart sound and a rough burst sound can be heard at the left heart margin, which is often consistent with the heartbeat and may be produced by the movement of gas in the thoracic cavity due to the pulsation of the heart, which changes with the change of body position. (Signs can be different due to different degrees of severity) Scratching sign positive: put the stethoscope chest piece in the middle of the patient’s chest, and then at a distance of <6cm from the midline, scratch the chest wall bilaterally with the same force with your fingers, obviously the loud and rough side is the pneumothorax side. X-ray examination: the translucency of the pneumothorax area increases, the lung texture disappears, if there is no adhesion of the lung to the lung door contraction, a mass, the edge of the hairline dirty layer pleural shadow is visible, if there is pleural adhesion, visible strip or band shadow, or multi-room pneumothorax shadow. In massive pneumothorax, the mediastinum may be displaced to the healthy side, the transverse septum may drop, and a fluid plane may be seen if pleural effusion is present. If there is a translucent band around the edge of the heart, the presence of mediastinal emphysema is mostly considered. A small amount of limited pneumothorax can sometimes be detected by multi-axis fluoroscopy, lateral film or CT examination. Laboratory examination: subcutaneous emphysema is not abnormally altered in mild cases, while more severe cases have varying degrees of hypoxia. A decrease in arterial oxygen saturation and partial pressure of oxygen can be seen, and in severe cases, an increase in partial pressure of carbon dioxide can be seen. In severe cases, increased blood carbon dioxide partial pressure may be seen. In the presence of intrathoracic infection or intrapulmonary infection, there is an increase in total white blood cells and neutrophilia. Thoracoscopy: It is an important tool for diagnosis and treatment of pleural diseases. In order to find the cause of spontaneous pneumothorax and guide the selection of reasonable treatment methods, thoracoscopy is the most ideal, generally under local anesthesia, a single jack type thoracoscope is used to examine the pleural cavity directly and carefully and comprehensively, and the lesions can be photographed or biopsied, or drugs can be sprayed in as well as surgical treatment. This examination method is simple, safe, with high diagnostic rate and good therapeutic effect. The postoperative complications are transient fever and subcutaneous emphysema, and the incidence is low, and the spontaneous pneumothorax can still be graded according to the results of thoracoscopy in order to guide the treatment.