The main hazards of rib fracture are as follows: 1. If the fracture is severely misaligned, it may stab the blood vessels of the chest wall and lead to a hemothorax. 2. If the fracture end stabs the lung, it may lead to a pneumothorax due to air leakage, or it may lead to a blood clot due to damage to the blood vessels of the lung. If the pneumothorax is very strong will lead to lung compression and serious breathing difficulties. 3, if the large blood vessels of the lung or lead to a stab wound of the heart there is a large amount of bleeding in the chest cavity, serious hemorrhagic shock and lead to life-threatening. If the stab wound to the heart may also lead to heart stopping, leading directly to death.