The self-healing time of mild pneumothorax is mainly related to the type of pneumothorax and the individual condition of the patient, which requires specific analysis of the problem. Mild pneumothorax refers to pneumothorax with less than 30% lung compression, which can be manifested as mild chest pain, cough, poor deep breathing, etc. Because the lung compression is less and does not affect the respiratory function, it can generally heal by itself and no special treatment such as surgery or closed chest drainage is recommended. If it is a spontaneous mild pneumothorax, sometimes there may be recurrent attacks and it usually takes about 15 days to be completely absorbed by itself. In case of traumatic pneumothorax, it usually does not recur after the rupture is sealed and the recovery is relatively fast, and can be recovered in 7-10 days. However, if the rupture is too large or the patient is older or in poor nutritional condition, it will take longer time for self-absorption and may be admitted to hospital for treatment if necessary. In daily life, patients with mild pneumothorax should pay attention to more rest, prohibit smoking, avoid strenuous exercise or forceful coughing, and seek timely medical treatment if serious symptoms such as chest tightness and difficulty in breathing occur.