Babies who fall on their heads have an incubation period because a fall on the head, especially if it causes a brain hemorrhage, will have a chronic hemorrhagic incubation process, usually showing pathological symptoms in two days. If the skull suffers an injury, most children will show symptoms within three days, and a few children will show symptoms only a week after the head trauma. Children with head trauma usually need to be observed for 3-7 days, and those with severe injuries usually respond quickly with symptoms such as vomiting, nausea and unconsciousness, while those with milder injuries may not have symptoms at the time, but slowly develop symptoms over time. Therefore, it is important to observe carefully and seek medical attention immediately when symptoms appear. If necessary, it is best to perform a cranial CT or MRI to rule out intracranial hemorrhage, and hospitalization is recommended for observation if there are precursors of bleeding. Even if no injury is detected, do not let your guard down at home to avoid delayed intracranial or subdural hemorrhage and try not to let your child have strenuous activities. The chances of serious injury from a fall on the head are low, but not unimportant. Parents should still closely observe the child’s physical state and seek medical attention when symptoms appear.