Colds mostly refer to acute upper respiratory tract infections and influenza, upper respiratory tract infections are generally mild, short-lived, self-limiting and have a relatively good prognosis, but there is a certain degree of contagiousness. Influenza is mostly caused by influenza virus, which is an acute respiratory infectious disease. Preventive measures for influenza are as follows: 1. enhance physical fitness, wash hands regularly, keep the environment clean and ventilated; 2. minimize activities in crowded places during the epidemic season and avoid contact with patients with respiratory infections; 3. maintain respiratory hygiene; 4. wear a mask when going to public places or during medical treatment; 5. get vaccinated against influenza.