After a child falls on the head, if the fall is very mild and there is no concussive injury to the brain or no significant bleeding in the skull, the child will not vomit. If the fall is severe and there is a concussive injury to the brain or intracranial hemorrhage, the child may experience headache, jet vomiting, or even drowsiness and convulsions. It is generally recommended to observe the child for 48 hours after the head fall, more than 48 hours if the child does not show any symptoms, generally not a big problem. If there is bleeding, the child will gradually show symptoms within 48 hours and needs to be taken for a head MRI or CT to clarify the extent of the lesion.