There may be an incubation period after a baby falls on the back of the head, and in some cases it may take 2-3 days for symptoms to become apparent. The first thing a baby will do after a fall to the back of the head is to cry, and most babies may have adverse reactions such as vomiting and convulsions right then and there. But some babies after the fall to the back of the head may be because of the pain has been crying until sleep, in the baby sleep some adverse symptoms can not be manifested, wake up after sleep, some even 2-3 days after the confusion, frequent vomiting and other symptoms, so the fall to the back of the head is a certain latency period. After the baby fell to the back of the head, first of all, we must promptly calm the baby to stop crying, when the symptoms of discomfort sent to the hospital for examination, to observe whether there is intracranial hemorrhage and other conditions.