Influenza is an infection of the nose, throat, and lungs (respiratory tract) that is caused by a virus. Influenza can happen any during the year, but most cases happen in the winter months.
You may also hear influenza called flu, bird flu, or H1N1. All of these mean the same thing as influenza and the information below applies to all of them.
Influenza is spread through the air. The virus gets in the air when someone with the disease coughs, sneezes, or even talks. People who breathe in the virus can get sick. It can also be spread by touching objects that have been coughed or sneezed on by someone with the virus.
Most people who get sick with influenza get better. However, influenza causes about 12,200 people to be admitted to the hospital and about 3,500 deaths in Canada each year. There is a higher risk of getting complications from influenza for children 6 to 59 months of age, pregnant women, people 65 years or older, and people with chronic health problems. Complications of influenza can include pneumonia, ear and sinus infections, and dehydration. Influenza can also make chronic medical problems (e.g., congestive heart failure, asthma, diabetes) worse.
The symptoms of influenza are fever of 38.5°C (101.3°F) or higher that starts suddenly, cough, headache, muscle aches, loss of appetite, and feeling tired.
People can spread (are contagious) influenza the day before they have symptoms and for 5 days after symptoms start.
chills, aches, pains
usually and often severe
usually and can be severe
loss of appetite
runny nose or sneezing
involves whole body
stomach and bowels only
symptoms appear quickly
pneumonia (can be life-threatening)
sinus infectionear infection
Current as of: August 10, 2016
Author: Influenza Immunization Program, Alberta Health Services