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Kids Health Info

Flu (influenza)

  • Key points

    • The flu – also known as influenza – is an infection caused by influenza viruses.
    • It is a very contagious illness, so it is important to practice good hygiene to stop the spread.
    • Antibiotics cannot treat the flu.
    • If your child has the flu, they should get plenty of rest and drink lots of fluids.
    • Most children recover from the flu within a week, but their tiredness and cough may last longer.
    • See a doctor or health professional if your child has the flu and becomes more unwell, has trouble breathing or shows signs of dehydration.
    • Vaccination is the best way to prevent the flu and its serious complications.

    What is the flu?

    The flu – also known as influenza – is a respiratory illness caused by a type of influenza virus. It is very contagious, spreading easily from one person to another.

    In most cases, the flu has symptoms similar to a cold. However, tiredness, lethargy and high fevers are more prominent, and the illness tends to last longer. The flu can lead to more serious sickness and complications – especially in very young children and those with ongoing medical conditions.

    The flu is more common in autumn and winter. Each year, flu viruses change, and so do the types of flu spreading in the community. Occasionally, one of these strains can cause a more widespread or serious outbreak.

    Signs and symptoms of the flu

    The flu usually starts with a sudden fever and many of the following symptoms:

    • Sore throat
    • Runny nose
    • Dry cough
    • Headache
    • Aches and pains
    • Tiredness and lethargy
    • Nausea, vomiting and/or diarrhoea.

    Mild flu

    If your child has had the flu before or the flu vaccine, they may have some immunity to flu viruses. This means it will be easier for their body to fight off infection. In most cases, children with some immunity will have a mild flu lasting less than a week.

    Moderate to severe flu

    Children with moderate flu usually have the same symptoms as mild flu, along with long-lasting high fevers and significant lethargy. These symptoms can last up to seven days.

    Sometimes, the flu can lead to complications like pneumonia (lung infection), which can make breathing hard for the child.

    In rare cases, the flu may cause inflammation in organs like the heart (myocarditis) or brain (encephalitis) or even multi-organ failure (lung or kidney failure). Children with these conditions need treatment in hospital.

    How to care for the flu at home

    Most children can safely recover from the flu at home within a week. The best things you can do to help your child are:

    As the flu is a virus, antibiotics cannot treat it. A doctor may only prescribe antibiotics if your child has another infection caused by bacteria, such as a chest or ear infection.

    Sometimes, a doctor may prescribe antiviral medicines to children with chronic medical conditions or severe flu symptoms.

    Watch your child for any signs they are getting sicker, such as:

    • not eating or drinking enough
    • dehydration, with symptoms like cold hands and feet, sunken eyes, urinating (peeing) less often
    • trouble breathing
    • worsening tiredness and lethargy
    • acting extremely irritable.

    See a doctor or health professional if your child’s condition gets worse.

    When to get help

    Call an ambulance (000) if:
    • your child is struggling to breathe and cannot catch their breath.
    • your child’s skin looks bluish or grey.
    • your child is not waking up or not interacting.

    Go to a hospital if:
    • your child is extremely irritable or confused.
    • your child has severe or ongoing vomiting.
    • your child is dehydrated and not drinking fluids.

    See a doctor or health professional if:
    • your child has a weakened immune system.
    • your child has a long-term medical condition, such as asthma or heart disease.
    • your child is not eating or drinking and is peeing less than usual.
    • your child is working harder to breathe than normal.
    • your child’s flu symptoms improve but then return with fever (temperature of 38°C or more) and trouble breathing.
    • your child has a fever (temperature of 38°C or more) with a rash.

    Look after your child at home if:
    • they are drinking enough fluids.
    • their breathing is normal.
    • they are lethargic sometimes but not all the time.
    • it is not hard to wake them up.
    • they start getting better within seven days.

    Common questions about the flu

    Is the flu contagious?

    The flu is a very contagious illness. A person with the flu can spread the virus from the day before their symptoms start until about a week after. The flu virus spreads easily from person to person through tiny droplets in the air, such as when an infected person coughs, sneezes or talks. It can also spread through virus droplets on hands or objects like cups and door handles.

    What is the best way to stop my child getting the flu?

    The flu vaccine is the best way to stop your child getting the flu. Everyone aged six months and older should get a flu shot every year before the start of winter. Vaccination is especially important if your child has a chronic medical condition. Two doses are required in the first year of vaccination for children under nine years.

    Your child will need a new flu vaccine annually as flu viruses change yearly.

    How can I stop others in my household from getting the flu when my child is sick?

    Practising good hygiene is the best way to prevent others in your house from getting the flu. This means washing hands regularly, not sharing cups or cutlery, encouraging your child to cough and sneeze into their elbow, using tissues and throwing them in the bin immediately before washing hands, and regularly cleaning surfaces.

    How long should my child stay home from school or childcare with the flu?

    If your child has flu symptoms, you should keep them home from school or childcare until they are well again. This usually takes about a week after their symptoms start.

    What natural remedies can I give my child to help them feel better?

    We do not recommend giving medical or natural treatments to children without professional medical advice. Vitamins will not make your child get better more quickly.

    Should I give my child cold and flu medicine?

    Over-the-counter medication such as paracetamol and/or ibuprofen can help your child’s pain, fever and discomfort. Saline nasal (nose) spray can be good for blocked noses. Cough medicines and decongestants are not recommended for flu symptoms. If your child is over 12 months of age, honey can soothe their cough. You should not give honey to children under one-year-old due to the risk of botulism – a serious disease that causes paralysis.

    Is the flu shot safe?

    All vaccines currently available in Australia must pass thorough safety testing before being approved for use by the Therapeutic Goods Administration (TGA). As the flu vaccine contains an inactive form of the virus, it cannot give your child the flu. It can, however, cause milder symptoms that may resemble the common cold.

    I have heard of people catching the flu even though they have had the vaccine. Does the vaccine work?

    The flu vaccine does not cover all strains of the flu virus, but it is made each year to cover the most common and severe ones. While the vaccine may not always stop your child from getting the flu, it will make the illness milder and reduce the risk of complications.

    My child is getting better after the flu, but they have sore legs and trouble walking. Is this normal?

    Muscle inflammation (myositis) can cause calf pain and trouble walking. These symptoms usually get better within a few days. However, it is best to see a doctor to confirm this diagnosis.

      This podcast is also available in audio format below, and on Apple Podcasts and Spotify.

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      Winter wellness season: Colds, flu and COVID

      For more information

      Developed by The Royal Children’s Hospital Emergency department. We acknowledge the input of RCH consumers and carers.

      Reviewed April 2025

      Please always seek the most recent advice from a registered and practising clinician.


    Disclaimer

    This information is intended to support, not replace, discussion with your doctor or healthcare professionals. The authors of these consumer health information handouts have made a considerable effort to ensure the information is accurate, up to date and easy to understand. The Royal Children's Hospital Melbourne accepts no responsibility for any inaccuracies, information perceived as misleading, or the success of any treatment regimen detailed in these handouts. Information contained in the handouts is updated regularly and therefore you should always check you are referring to the most recent version of the handout. The onus is on you, the user, to ensure that you have downloaded the most up-to-date version of a consumer health information handout.