The danger period of falling to the head is related to the severity of the patient’s fall and should be analyzed in a problem-specific manner, not as a generalization. After a fall to the head, it is recommended to promptly conduct a head CT examination to see if there is a brain contusion, brain hemorrhage and other conditions. If there is only a minor injury, no nausea, vomiting, headache and other symptoms, there is generally no life threatening. However, if the head CT shows the presence of obvious brain contusion, brain hemorrhage, etc., it may be life-threatening and needs to be closely observed. Among them, the risk period for patients with mild cranial injury is 24 hours, for patients with moderate cranial injury is 72 hours, and for patients with severe cranial injury is usually 7-10 days. After a fall, if a patient has symptoms of discomfort, he or she should go to the neurosurgery department of the hospital in a timely manner, conduct a cranial CT examination to understand the intracranial situation, clarify whether there is bleeding, closely observe the patient’s consciousness and pupil changes, and if necessary, timely surgical intervention is required.