The flu is a contagious respiratory illness caused by influenza viruses. It can cause mild to severe illness, and at times can lead to death.

The major symptoms to be aware of are high fever, headache, extreme tiredness, dry cough, sore throat, runny or stuffy nose, muscle aches, nausea, and vomiting or diarrhea.

Every year in the United States, on average, between 5 to 20 percent of the population get the flu. The best way to prevent this illness is by getting a flu vaccination each fall.