Influenza A can be distinguished from Influenza B by pathogen, epidemiology, symptomatic level and prognosis. 1. Pathogen: Influenza A is caused by the influenza A (H1N1) virus, while influenza B is caused by the influenza B virus, which can be recognized by laboratory tests such as viral antigen detection and virus isolation and culture. 2. Epidemiology: Influenza A has an incubation period of about 1~7 days and is contagious from 1 day before to 5~7 days after the onset of the disease. Influenza B has an incubation period of about 4 days and is contagious from 1 to 7 days after infection. Moreover, influenza A is an outbreak of widespread bleeding, and the virus is prone to mutation. However, Influenza B is a limited epidemic and less severe. 3. Degree of symptoms: both will appear fever, chills, muscle aches and other symptoms. However, since Influenza A is more contagious, the symptoms are more severe than those of Influenza B. 4. Prognosis: Although the prognosis for both is good after standardized treatment, influenza B in milder cases often resolves itself without treatment. All in all, whether it is type A or type B influenza, patients need to go to the hospital, cooperate with the physician’s diagnosis and treatment program, so as not to delay the disease.