婴幼儿抵抗力差，无论是着凉、受热，还是积食、过累，都可以成为诱因，使他们患“上感”（上呼吸道感染），发烧、流鼻涕、咳嗽。有的孩子，病初是“上感”，几天以后病情变了，脸色青灰，精神极差，甚至发生惊厥。到了医院，医生会埋怨几句：“怎么肺炎这么重了，才到医院来 Infants and young children with poor immunity, whether it is cold, heat, or plot food, tired, can be incentives to make them feel “flu” (upper respiratory tract infection), fever, runny nose, cough. Some children, the beginning of the disease is “on the flu,” a few days later the condition changed, his face gray, very poor spirit, and even convulsions. To the hospital, the doctor will complain a few words: "how pneumonia is so heavy, came to the hospital