When a patient suffers a pneumothorax, the trachea is displaced to the opposite side, and the heart is also shifted to the opposite side. In cases of left-sided pneumothorax, the heart's dullness boundary and the upper boundary of the liver during right-sided pneumothorax are both undetectable. There can be manifestations of subcutaneous emphysema in the neck, chest, and even the head and abdomen. The patient may exhibit diminished respiratory movements and a significant reduction or absence of breath sounds. When a small amount of air accumulates in the pleural cavity, weakened breath sounds on the affected side may be the only suspicious sign.