The h3n2 influenza is generally known as influenza A H3N2. Influenza A H3N2 is generally contagious and can be spread through the respiratory tract by droplets. Influenza A H3N2 belongs to a pandemic seasonal influenza A virus, with a certain degree of contagiousness. It can be transmitted via droplets through the respiratory tract, mainly through the respiratory tracts of a variety of animals, such as dogs, ducks and chickens. Patients will show symptoms of influenza, such as diarrhea, vomiting, coughing, sore throat, muscle aches, headache, etc. In severe cases, it may be followed by pneumonia and respiratory failure, or even death. Currently, vaccination is available, thus effectively preventing H3N2 virus infection. At the same time, it is necessary to ensure sufficient rest time, wash hands frequently and maintain indoor ventilation. Once diagnosed with Influenza A (H3N2), patients should actively cooperate with doctors to take relevant treatment measures.