Flu facts. What is influenza?
Influenza, commonly called 'the flu', is an illness caused by the influenza virus. The virus is passed form person to person by sneezing or coughing. Typical symptoms of influenza include fever, cough, sore throat, fatigue, muscle aches, headaches, runny nose and watery eyes.
D000368:Aged; D006801:Humans; D007114:Immunization; D007251:Influenza, Human / Q000150:complications / Q000517:prevention & control*; D012307:Risk Factors