Initial symptoms of H3N2 influenza are similar to those of the common flu, with early onset of fever, malaise, cough, sore throat, and in some cases diarrhea and vomiting. H3N2 influenza is a subtype of influenza virus. Mild H3N2 influenza symptoms are similar to those of the common cold and should not be identified, but its fever and systemic symptoms are more obvious. Severe H3N2 influenza can be followed by pneumonia manifestations, and even acute respiratory distress and shock. It often occurs in the elderly, young children, and people with chronic underlying diseases. H3N2 influenza incubation period is relatively short, can be 1 to 3 days, the shortest incubation period is only a few hours, early fever can appear, accompanied by headache, muscle pain, similar situations, should consider the occurrence of influenza. In addition, the best way to prevent H3N2 influenza that is vaccinated, develop good hygiene habits, go out, wear a mask in crowded places, can effectively control the spread of influenza, the specific can consult a professional physician.