What is the flu? The flu, also known as influenza, is a common respiratory (nose, throat, and lung) infection. It can cause fever, muscle aches, extreme tiredness, sore throat, headaches, and a runny or stuffy nose (see "Flu symptoms" to learn more). About 10% to 25% of Canadians get the flu each year.
Flu symptoms tend to begin quite suddenly. The most common flu symptoms are: dry cough (may last for weeks after a bout of the flu) extreme tiredness (may continue for weeks after the flu is over) fever (usually lasts 1 to 2 days, although it may last as long as 5 days, and may return later) headache muscle and body aches or stiffness (tend to appear early and then start to fade within 2 to 4 days) runny or stuffy nose sneezing sore throat Other flu symptoms include: nausea, vomiting, or diarrhea (more common with children poor appetite sweating Usually, flu symptoms last for 7 to 10 days.
Flu complications can lead to hospitalization and may even be fatal. In Canada, about 12,000 people are hospitalized each year due to flu complications. And every year, about 3,500 Canadians die from the flu and flu complications.