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Flu (Influenza)

Influenza, also known as the flu, is a contagious respiratory condition caused by the influenza A or B viruses. Generally, the flu season starts in the fall and can last until spring. The influenza virus spreads very easily from person to person. It can survive for up to 2 days on contaminated surfaces or objects. The risk of contagion begins 24 hours before the first symptoms appear and can last up to 7 days afterwards. Sneezing, coughing or even talking releases droplets into the air that can infect other people.

Is it the flu or is it a cold?

It can be difficult to tell the difference between a flu and a cold. At first glance, they are similar but very different diseases. Cold symptoms are usually mild while flu symptoms are more severe. In addition, colds are common and mainly infect the nose and throat, while the less common flu can also affect the lungs.

Symptoms Cold Flu
Fever Rare Usually high (38 to 40°), suddent, lasting 3-4 days
Headaches Rare Significant
Generalized muscular pain Mild Common, sometimes acute
Fatigue and weakness Insignificant Extreme, can last up to one month
Loss of appetite Never Common
Exhaustion Never Rapid and significant
Runny nose Common Exceptional
Sneezing Common Exceptional
Sore throat Common Exceptional
Chest pains, cough Mild to moderate Common and can become persistent
Complications Sinus congestion and  ear aches Life threathening bronchitis and pneumonia
N.B. If any of these symptoms persist, please see your doctor.

Persons at risk

Anyone can get the flu. Influenza is a severe disease, and older people and young children are at the greatest risk of influenza and its complications. These are people at risk of complications.

The people said to be at risk of complications include:

  • people with certain chronic diseases (COPD, asthma, diabetes, cancer, etc.);
  • children aged 6 months to 5 years;
  • people aged 60 and over;
  • pregnant women (especially 2nd and 3rd trimester);
  • people with a weakened immune system (HIV, organ transplants, etc.).
  • people living in long-term care centres or nursing homes, regardless of age;
  • people with morbid obesity (BMI> 40); and
  • people of Aboriginal origin;
  • workers in contact with the population at risk of complications (health care workers, daycare workers, etc.).

Signs and symptoms

Even though the flu is a respiratory illness, it affects the entire body. Usually, acute symptoms appear suddenly. Fever sets in quickly and is accompanied by chills, general weakness, loss of appetite and sharp muscle aches and pains throughout the body. Most people recover within 5 to 10 days without experiencing complications.

However, fatigue and cough may persist for up to 2 weeks or more. Gastrointestinal symptoms such as nausea, vomiting and diarrhea can sometimes accompany the flu, but they are more common in children.

You may experience one or more of the following symptoms:

  • Fever
  • Cough
  • Sore throat
  • Fatigue and weakness
  • Muscle aches and pains
  • Headaches
  • Loss of appetite
  • Nasal congestion or runny nose

Complications of influenza can include dehydration, sinusitis, ear infection, bronchitis and pneumonia.

When to seek healthcare?

If you think you may be experiencing flu symptoms, our toll-free health line (8-1-1) is a good resource to guide you.

You should see a doctor if you have flu symptoms in addition to one or more of the following symptoms:

  • Loss of appetite
  • Shortness of breath, difficulty and pain in breathing
  • Bluish lips and/or fingers
  • Dizziness
  • Confusion
  • High fever that persists for more than 3 days
  • Persistent vomiting
  • Blood in secretions

A child who has the flu who does not eat, drink or play should see a doctor.


In uncomplicated cases, flu symptoms usually disappear without treatment. It is especially recommended to get some rest and take care of yourself at home to avoid infecting others.

Here are some ways to relieve your symptoms:

  • Get some rest
  • Drink plenty of water
  • Take over-the-counter fever medications such as acetaminophen (Tylenols®), ibuprofen (Advil®) and acetylsalicylic acid (Aspirin®)

With all over-the-counter medications, don’t forget to read the label to make sure that the treatment is appropriate for your situation (age, health problems, etc.) or consult your pharmacist, who will be able to guide you.

In some cases, your doctor may also prescribe an antiviral medication administered orally. To be effective, it must be taken within 48 hours of the onset of the first flu symptoms.

Antiviral medications

Antiviral drugs such as amantadine, zanamivir and oseltamivir can prevent and treat influenza caused by type A or B virus. However, they are not intended to replace the annual vaccine for people at risk. Antiviral medications will reduce flu symptoms if given within 24 to 48 hours of the onset of symptoms. Note that they do not interfere with the action of the vaccine given by injection.

These medications should not be considered as a substitute for vaccination, which remains the best way to prevent the flu.

Tips and prevention

The flu can be prevented by getting a flu shot every fall. The vaccine allows the body to produce the antibodies that will protect the body for the five to six months of the flu season. The annual vaccination helps prevent the flu and reduces the severity of the illness. The best time to get the flu shot is at the beginning of the flu season in October and November.

Here are some simple and effective ways to protect yourself from the flu:

  • Wash your hands frequently
  • Clean the most frequently used surfaces (doorknobs, counter surfaces, etc.).
  • Limit contact with sick people
  • Get vaccinated (see the Vaccination tab for more information on the flu vaccine).


In 2011, Quebec had the lowest vaccination rate in Canada with 27% of its population having received the vaccine. In addition, 25% of Quebecers said they had contracted the flu, the highest rate in the country.

By contrast, British Columbia had a vaccination rate of 52% and, as a result, only 10% of the population was affected by the flu that year.

In Quebec, more than 300 deaths each year are attributable to the flu virus. It is therefore not a problem to be taken lightly.

Every year in Quebec, new flu vaccines are available because the flu virus changes frequently. These vaccines have the advantage of containing the new strains of the virus circulating in North America for the current year.

There are two types of vaccine on the market, the inactivated and the attenuated vaccine. The inactivated vaccine is given by injection and contains non-living parts of the virus. The attenuated vaccine is given nasally and contains live virus that has been attenuated. The attenuated vaccine is particularly used in children because it is more effective than inactivated vaccines. The protection provided by the vaccines appears about two weeks after administration and covers the entire period during which the virus is present. It is still possible to get the flu despite the protection provided.

  • Who should get the flu vaccine?

  • Who should not get the flu vaccine?

  • Are there any risks associated with the vaccine?

Visit the health and wellness portal to learn more about pneumococcal infections

Health and well-being portal

Did you know that

The Quebec Lung Association offers direct services to the population. For more information, visit our Patient Resources section.