Flu (influenza): Symptoms and treatment

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Flu symptoms

Some people only get mildly ill. Others get very sick.

Flu symptoms appear 1 to 4 days after exposure to the virus. Usually they include the sudden appearance of:

  • fever
  • cough
  • muscle aches and pain

Other common symptoms may include:

  • headache
  • chills
  • fatigue (tiredness)
  • loss of appetite
  • sore throat
  • runny or stuffy nose

Some people (especially children) may also have:

  • diarrhea
  • nausea and vomiting

Additional symptoms to watch for in children

As a parent, you know your child best. Talk to your healthcare provider right away if you notice any of these symptoms:

  • not drinking or eating as usual
  • not waking up or interacting with others
  • irritable (not wanting to play or be held)

Contagious period

People infected with the flu virus can spread it to others:

  • starting 1 day before the first symptoms
  • until approximately 5 days after the first symptoms

If you get the flu

If you do get sick, stay home. Avoid close contact with other people until you feel well enough to get back to your usual day-to-day activities. This will help prevent the spread of the flu. Most people recover from the flu in 7 to 10 days.

If you are a person at high risk of flu-related complications and develop flu symptoms, contact your healthcare provider. Tell them about your flu symptoms over the phone before your appointment. That way, they can arrange to see you without exposing other people.

When to seek immediate attention

Visit your nearest hospital if you develop any of these serious symptoms:

  • shortness of breath, rapid breathing or difficulty breathing
  • chest pain
  • bluish or grey skin colour
  • bloody or coloured mucus/spit
  • sudden dizziness or confusion
  • severe or persistent vomiting
  • high fever lasting more than three days
  • low blood pressure

Possible complications of the flu

  • pneumonia and respiratory failure
  • worsening of chronic health conditions

Other severe outcomes of the flu

  • hospitalization
  • death

How the flu is diagnosed

The flu is usually diagnosed by your healthcare provider based on:

  • symptoms
  • laboratory tests

Flu treatment

Flu symptoms can be treated with:

  • rest
  • fluids, like water
  • medication to reduce any fever or aches

In some cases your healthcare provider may prescribe medication, especially if you are:

  • at high risk for flu-related complications
  • very sick with severe symptoms

Over-the-counter cough and flu medicine should not be given to children younger than 6 years old. It is only safe to do so if you are advised to by your healthcare provider.

Posters and videos to share

Share the moment not the flu

With described video

Transcript - Share the moment, not the flu


A young girl is given a dance outfit by her mom, who is suffering from flu-like symptoms, at the doorstep of the family home, and they wave goodbye to each other.

A mobile phone held up by the father's hands as he records the little girl's dance performance.

Close up of a tablet on a table as the video of the girl's performance is being streamed live.

Medium shot of the sick mom watching the video on the tablet in her kitchen. She smiles and claps.


URL ON-SCREEN: Canada.ca/Flu

TEXT ON-SCREEN: Government of Canada logo

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