Influenza: What is influenza (flu)? What are the symptoms?
Influenza (flu) is a contagious respiratory illness caused by influenza viruses. The flu can cause mild to severe illness. Symptoms often come on suddenly and include fever or feeling feverish/chills, cough, sore throat, runny or stuffy nose, muscle or body aches, headaches, fatigue (tiredness), and some people may have vomiting or diarrhea. More information can be found here.