Prevention of pneumonia: 1, the residence time in polluted environment should be reduced, such as poor air circulation or cold and dry environment, which is harmful to the protection of airway epithelium and easy to be infected by bacteria and viruses. If you need to wear a mask when entering a polluted environment, it is recommended to use a humidifier in a dry environment, but the humidifier must be cleaned regularly. 2. Stay away from patients with lung infection. Lung infection is not contagious, but tuberculosis, viruses, infectious bacteria or viruses are contagious, and most of them are not contagious. But for people with low immunity, try to stay away from patients with lung infection. If there are bacteria in sputum, it will be contagious. 3, physical exercise to enhance physical fitness, reasonable life, to ensure adequate sleep, to prevent the invasion of bacteria and viruses. 4. For the elderly with high incidence and poor health, it is recommended to inject pneumonia vaccine.