Alberta Health Services
Health Information
Influenza, sometimes called the flu, is an infection of the nose, throat, and lungs that is caused by a virus. Influenza is a respiratory illness.
The number of people who get sick with influenza is different year to year. On average each year, more than 12,000 people in Canada have to stay in a hospital because of influenza, and 3,500 people die from it.
Learn more about influenza.
Everyone is at risk of influenza. The time when people are at greatest risk is called influenza season. It generally happens every year starting in late fall and lasting through the winter.
Influenza can make you very sick and lead to other health problems, especially if:
Influenza can spread in the following ways:
You can spread influenza before symptoms start.
Influenza is caused by a different virus than COVID-19, the common cold, and gastrointestinal illness (sometimes called the stomach “flu”). Although the symptoms of these diseases can be similar, there are differences:
Symptoms start suddenly and may include:
Other symptoms may include feeling sick to your stomach (nausea), vomiting (throwing up), or having loose stool (diarrhea). These are more common in young children.
In some cases, influenza can lead to a lung infection (pneumonia) or make other health problems worse. Even healthy, young people can get very sick or die from influenza. Learn more about health problems from influenza.
Most people can treat influenza symptoms at home. Home treatment includes resting, drinking plenty of fluids, and taking medicine to lower your fever.
Some people need to go to the hospital for treatment.
Everyone in Alberta age 6 months and older is encouraged to get the influenza vaccine each year.
The influenza vaccine is offered for free in Alberta every year starting in mid to late October.
There are many types of influenza vaccines. Every year, Alberta Health looks at information about influenza to help them decide which vaccines to offer.
You need to get the vaccine every year because influenza viruses change. A new vaccine is made each year to protect against the influenza viruses most likely to cause illness in that year. The best time to get the vaccine is October or November.
Learn more about the influenza vaccine.
HEALTH PROFESIONALS Visit Influenza Immunization Information for Health Professionals for resources to implement a safe and effective influenza immunization program.
To stop influenza from spreading:
If you are pregnant and get influenza, you have a higher risk of serious health problems and needing treatment in the hospital. The illness could also cause a problem for your baby, such as being born too soon (premature birth).
Getting the influenza vaccine while you are pregnant has many benefits:
It is safe to get the influenza vaccine while pregnant. The injected vaccine is recommended if you are pregnant. The nasal spray influenza vaccine is not recommended if you are pregnant.
Both types of influenza vaccines (injected and nasal spray) are safe to get when breastfeeding.
Learn more about immunization and pregnancy.