The baby fell on the head, generally need to be closely observed for 72 hours. This observation is because after the baby fell on the head, he may not have any big reaction, may be crying for a while after the child coaxed not too big problem, but often the child may be accompanied by intracranial hemorrhage, or even skull fracture, and other conditions. When the intracranial hemorrhage is just after the injury, sometimes the amount is still relatively small, and it may be difficult to detect it by CT or MRI at this time. If the parents do not care, it is possible that the child’s bleeding will continue to increase during this period, and after increasing to a certain amount, it will lead to brain herniation, or even serious brain hemorrhage, which will stimulate the child to vomit and have headaches, and the family will not be able to find it, or even life-threatening situations. Within 72 hours, the family must observe the child closely and wake him/her up regularly to see if he/she is drowsy or difficult to wake up. In addition, if the child appears violent projectile vomiting or crying, anxious crying and restlessness, difficult to put the child to sleep, this situation should always go to the hospital to review ct, to ct to prove that there is no fresh massive hemorrhage and skull fracture before, that is to say, the baby fell on the head at least 72 hours of observation.