Influenza A Symptoms 2024. Seasonal influenza (the flu) is an acute respiratory infection caused by influenza viruses. Flu symptoms can vary from person to person, but most people with influenza will experience some degree of fever, chills, headaches, body aches, congestion, coughing, and fatigue.
Influenza (the flu) is a viral infection that causes symptoms like fever and chills, sneezing, coughing and a sore throat. Telling the difference between cold and flu.