If it is a small amount of pneumothorax, the physical signs are generally not obvious, especially when patients with emphysema develop pneumothorax, it is difficult to detect any signs. However, when a larger amount of pneumothorax occurs, inspection will reveal that the affected side of the chest is bulging and respiratory movements are reduced. Upon palpation, the trachea usually shifts towards the healthy side, tactile fremitus on the affected side is reduced, percussion results in hyperresonance or tympany, and auscultation shows reduced breath sounds, which can disappear in severe cases.