About the Flu

What is flu?

Influenza, also known as influenza, is a common respiratory infection (nose, throat and lung). It can cause fever, muscle aches, extreme fatigue, sore throat, headache, runny nose or nasal congestion. An estimated 10% to 25% of Canadians get the flu each year.

What causes the flu, and how is it spread?

The flu is viral. It is caused by viruses that are not consistent from one year to another. There are three main types of influenza virus known as influenza A, B and C. Types A and B are the most common. They are deemed responsible for the designated flu "seasonal flu" that occurs during the winter (in Canada, flu season usually extends from early winter to early spring). Influenza type C uncomfortable, but does not cause so-called seasonal flu.

You may have heard of other viruses, including H1N1 or H3N2 by listening to the daily bulletins of information. This is because the virus of type A can be decomposed into sub-types: H (corresponding to the hemagglutinin) and N (which stands for "Neuraminidase") based on two proteins on their surface. It is the combination of different types of H and N determines the designations as H1N1 or H3N2. Sometimes a new type of influenza A appears against which the majority of the population is not immune. The virus can then spread rapidly among people around the world. This is a very wide spread pandemic flu.

You can get the flu if an influenza virus enters your body through the eyes, nose or mouth. This can happen when an infected person who is close to coughing or sneezing, or if you touch a surface (like a door knob or buttons on a lift) touched by an infected person and then you wear your fingers in your eyes, your nose or mouth.

Flu symptoms usually appear 2 or 3 days after exposure to the virus, although they may also occur only within 1 to 7 days. Influenza is highly contagious and can spread very rapidly among a group of people.

How the diagnosis of influenza is it placed?

Your doctor can usually diagnose flu symptoms on your own. It can also perform a physical exam, and recommend further analysis as a sputum culture or chest x-ray to rule out the possibility of complications from influenza such as pneumonia.

Sometimes it can be difficult to tell if you have the flu or a cold. With the tool: "Is it a cold or flu? "You will be able to distinguish the difference.