Encephalitis is an infection of the central nervous system. The symptoms of pediatric central nervous system infection are divided into two major areas: 1. Symptoms caused by infection and brain dysfunction: the most common are fever, convulsions, and impaired consciousness. The most common symptoms are fever, convulsions, and dysfunction of consciousness. The dysfunction of consciousness is divided into agitation, where the child may be crying, screaming, and irritable without being soothed. The temperature can be normal, or even the temperature does not rise, there is no crying, no movement, no noise, the milk does not eat or eat less than usual, is also to be alert to the presence of infection; 2, the symptoms of cranial hypertension: the main manifestations are headache, vomiting, serious cases will have brain herniation. In the event of brain herniation, the child’s heart rate, breathing, blood pressure, temperature and other vital signs will be affected, and there may even be sudden impairment of consciousness, and there may be impaired movement of the limbs. However, in small infants, the cranial sutures are not yet closed, and the symptoms of headache and vomiting are not obvious, and may only be manifested by a full bulge of fontanelle, a tense feeling, and an enlarged cranial suture.