Influenza is a contagious disease, mainly caused by the spread of the influenza virus among people. Patients may display symptoms such as sore throat, cough, and fever. The severity of influenza can vary. Typically, for people with normal immunity, influenza goes through a self-limiting process, and generally, patients can recover on their own without treatment in about 7 to 10 days. However, certain special populations, such as the elderly, infants, pregnant women, cancer patients, or those who have been taking immunosuppressive drugs for a long time, often experience prolonged symptoms after contracting influenza. Additionally, influenza can lead to influenza pneumonia, and in severe cases, it may cause myocarditis or meningitis, potentially leading to life-threatening conditions. Therefore, special attention should be paid to these vulnerable groups.