Children’s brain neurological development is incomplete, the psychological defense mechanism is not perfect, after being frightened can not be self-adjustment, easy to appear nervous, anxiety and other emotional reactions. Some children may become agitated, hyperactive, sleepless and crying after being frightened. Some children may be depressed, silent and depressed, slow in thinking and slow in action. Some children may also show signs of autonomic dysfunction such as rapid pulse, chest tightness, headache, dizziness, loss of appetite, cold hands and feet, frequent urination, and urgent urination. A small number of severe cases may show extreme emotional instability, imitating others or their younger selves symptoms.