What is H1N1 influenza?

Influenza A, short for "A-type influenza," is an acute respiratory infectious disease caused by infection with the Influenza A virus. It is highly contagious and can spread through respiratory droplets, direct contact, or indirect contact. Symptoms of Influenza A include fever, cough, sore throat, body aches, headache, chills, fatigue, and others; some patients may also experience diarrhea, vomiting, muscle pain, and red eyes. Special populations such as children, elderly individuals, people with chronic diseases, and pregnant women are more susceptible to Influenza A and may face higher risks of complications, such as pneumonia and acute respiratory distress syndrome.