Influenza, or simply the flu, is a viral, acute respiratory infection caused by the common influenza virus in a population. Influenza is highly contagious and rapidly spreads, leading to annual epidemics and historically causing influenza pandemics every few decades, sickening and even killing many people in a short period of time. A person can develop lasting immunity to the flu and a person will not get the flu repeatedly within a short period of time. Main Symptoms Fever, headache, myalgia, malaise, rhinitis, sore throat, and cough are symptoms of influenza virus infection. Among them, sudden high fever is a major typical symptom of influenza and the first symptom of influenza. The patient’s body temperature is usually as high as 39-40℃, and the high fever often lasts for 3-4 days. Influenza can aggravate underlying diseases (e.g. cardiopulmonary diseases) or cause pneumonia. Elderly people and those who suffer from various chronic diseases or have a weak constitution are prone to serious complications and a high mortality rate after influenza. Points for public prevention 1, maintain good personal and environmental hygiene; 2, wash your hands often, with soap and running water; 3, often open windows and ventilation, moderate exercise, adequate rest, avoid excessive fatigue; 4, coughing and sneezing to cover the nose and mouth, do not face others, influenza patients have to wear masks; 5, in the influenza period, try not to crowded places; try to wear masks; 6, get vaccinated against influenza. Children under 12 years of age are not allowed to receive inactivated whole virus vaccine. Transmission Transmission can be caused by coughing and sneezing of the infected person. Normal people may also be infected by touching objects with influenza viruses and then touching their own mouths and noses. Diagnosis The clinical manifestations of influenza are not very typical and can be easily confused with the common cold or acute respiratory infections. Therefore, influenza needs to be diagnosed by a combination of epidemiologic history, clinical symptoms and pathogenetic tests. 1. Influenza and the common cold (Shanggai, commonly known as typhoid) are different diseases. Influenza is caused by the influenza virus, while the common cold is caused by a variety of pathogens (a variety of viruses, bacteria, mycoplasma and chlamydia, etc.) infection. 2, people with influenza can produce lasting immunity, a person will not be repeated in a short period of time with influenza. While the common cold often appears in scattered cases, the patient is often accompanied by fatigue or a history of cold, can occur in any season, generally does not cause the death of the patient. Because it has many pathogens and immunity does not last long after infection, a person can get the common cold repeatedly within a short period of time. Key points of treatment After having influenza, proper isolation, rest, more boiled water, more ventilation and disinfection of the room, symptomatic treatment to alleviate symptoms and control bacterial secondary infections, and anti-influenza viral drugs can be taken in the early stage of the disease (within 48 hours). Patients with severe symptoms, such as severe pneumonia, extreme respiratory distress and high fever, require hospitalization. Complications Most patients recover within two weeks, but the elderly and those with chronic illnesses or frail bodies are prone to serious complications and have a higher mortality rate. Pneumonia, bronchitis, sinus and ear infections are complications of influenza.