Infants with concussion have the following symptoms: First, drowsiness: suddenly become drowsy in the near future and cannot be easily woken up. Second, vomiting: there is white foam at the mouth or severe vomiting of milk. Third, crying and fussiness. Fourthly, unresponsiveness: recent reaction is slow and there is uncoordinated movement. All of the above are considered to be symptoms caused by concussion. When an infant has a concussion, if there are no obvious positive signs on physical examination and cranial CT examination, most of them recover well and can be well recovered through proper rest. Generally, the symptoms of concussion last for about 24 hours. If the symptoms of concussion still do not disappear the next day, be alert to brain hemorrhage and have a CT examination of the head.