The flu is a highly contagious illness caused by the influenza virus. The influenza virus causes infections of the nose, throat and lungs.
In most people, the flu is uncomfortable and tiring. It can keep people in bed for days or even a couple of weeks. Some people are more at risk for serious complications from the flu, including seniors, young children, and people with long-term lung diseases like asthma and chronic obstructive pulmonary disease (COPD). Flu can make asthma symptoms worse and cause COPD flare-ups.
The flu can be fatal. Each year, regular seasonal flu causes around 4500 deaths in Canada.