The difference between infant lethargy and sleep is that, firstly, the degree of infant sleep is different, and secondly, the length of sleep is not the same. 1. Different degree of sleep: infants will show slow response to external stimuli when sleeping, not easy to be woken up by parents, or not easy to be woken up by pain stimulation. But normal sleep, the baby sleep can be called awake or pain stimulation wake up. 2. The length of infant sleep is not the same: infant sleep time is generally longer, far more than the baby’s normal sleep time of the day. If parents find that their babies have a tendency to lethargy, and the child’s spirit is not good, poor appetite, need to take the baby to the hospital for a detailed examination, to see if the baby has intracranial infection or hypoglycemia and so on. There is a big difference between drowsiness and sleep in babies. Parents need to pay attention to how long their babies sleep and how much they sleep. If parents find that the baby has the performance of lethargy must take the baby to the examination in a timely manner, to avoid the development of the disease.