After a traumatic injury in a car accident, the patient becomes unconscious and the risk period is usually 1-2 weeks. Of course, the risk period varies depending on the degree of injury and the severity of the patient’s condition. When a patient is unconscious after a car accident, the presence of cranial trauma is considered. Cranial trauma after a car accident can cause skull fracture, brain contusion, subarachnoid hemorrhage, epidural or subdural hematoma, all of which may cause coma. After a traumatic injury in a car accident, the relevant tests should be completed and patients with indications for surgery need to be treated surgically. The risk of coma after craniocerebral trauma is very high. After head trauma, the patient will develop cerebral edema, which usually lasts 1-2 weeks, and the patient is prone to respiratory and cardiac arrest during the cerebral edema period, and may develop serious complications such as stress ulcers and cardio-cerebral syndrome, so it is very dangerous.