Influenza A (H1N1) for acute respiratory infectious disease, the pathogen is a new type of influenza A (H1N1) virus, the population is generally susceptible to influenza A (H1N1) virus, and can be transmitted from person to person. Spring dry climate, low relative humidity of the air, more likely to lead to a scattered epidemic of influenza A, the author has recently participated in several cases of severe influenza A rescue, scattered cases have also led to panic in some people, so what are the clinical manifestations of influenza A, how to prevent influenza A? Shandong Qianfo Mountain Hospital Emergency Center Li Tao Once infected with influenza A, the early symptoms are similar to those of ordinary influenza, including fever, cough, sore throat, body aches, headache, chills and fatigue, and in some cases, diarrhea or vomiting, muscle pain or fatigue, and red eyes. In some patients, the disease can progress rapidly, with severe onset, sudden high fever, temperature over 39°C, and even severe pneumonia, acute respiratory distress syndrome (ARDS), pulmonary hemorrhage, pleural effusion, complete blood cytopenia, renal failure, sepsis, shock and Reye’s syndrome, respiratory failure and multi-organ damage, leading to death. The key to preventing influenza A is personal hygiene and protection. Avoid contact with respiratory patients with flu-like symptoms (fever, cough, runny nose, etc.) or pneumonia; pay attention to personal hygiene, wash hands frequently with soap and water, especially after coughing or sneezing; avoid contact with pigs or places where pigs are present; avoid crowded places; cover your mouth and nose with tissues when coughing or sneezing, and then throw the tissues in the garbage. Get up and live regularly, get enough sleep, and exercise moderately to keep your strength and improve your immune function; keep indoor ventilation.