The most severe case of rib fracture is what we call the occurrence of pneumothorax. Pneumothorax is caused by the puncture of the pleural cavity due to the fractured end, resulting in pneumothorax or hemothorax compressing the lung tissue, causing severe systemic respiratory and circulatory disorders. Severe pneumothorax can directly endanger life; this is the most serious harm of rib fractures. However, generally speaking, it is rare for a rib fracture to result in severe pneumothorax; most cases involve only a small amount of effusion or a small amount of air accumulation. Thus, generally, the harm from rib fractures is not very significant; the most severe harm is causing severe pneumothorax, affecting the overall respiratory and circulatory functions, and endangering life.