Influenza (flu)

What is influenza (flu)?

Influenza (flu) is a highly contagious viral infection of the respiratory tract that can cause severe illness and life-threatening complications (including pneumonia). It affects people of all ages. The flu is usually spread by breathing in droplets from coughs and sneezes that contain the virus.

The flu is a seasonal infection that usually occurs from April to September. Flu seasons vary in severity and duration from year to year. On average each year in Australia, influenza causes approximately 100 deaths and 5100 hospitalisations. These numbers are widely believed to under-represent the true burden of influenza disease in Australia.

Even healthy people can sometimes die from the flu. Some Victorians are at increased risk of serious disease and complications of flu, like young children, the elderly, pregnant women, Aboriginal and Torres Strait Islander people and people with a weakened immune system or a chronic medical condition.

During 2025, seasonal flu activity and COVID-19 are anticipated in Australia.

Vaccination is key to protecting yourself and those around you from the flu.

Symptoms of the flu

The most common symptoms of the flu are:

• sudden appearance of a high fever (38°C or more)
• a dry cough
• body aches (especially in the head, lower back and legs)
• feeling extremely weak and tired (and not wanting to get out of bed).

Other symptoms can be:

• chills
• aching behind the eyes
• loss of appetite
• sore throat
• runny or stuffy nose.

Having the flu is even more likely if you have been in contact with someone who already has it.

Diagnosing the flu

Flu and other kinds of viruses can only be confirmed by a doctor after a nose or throat swab has returned positive results.

Difference between the flu and COVID-19

The symptoms of COVID-19 and the flu can be similar.

If you are unwell with flu-like symptoms, contact your GP to check if you require COVID-19 testing.

The symptoms of COVID-19 to watch out for are:

• loss or change in sense of smell or taste
• fever
• chills or sweats
• cough
• sore throat
• shortness of breath
• runny nose.

Some people may also experience headache, muscle soreness, stuffy nose, nausea, vomiting and diarrhoea.

What to expect with the flu

Symptoms of the flu can hit very quickly and may last several weeks. A bout of the flu typically follows this pattern:

• Days 1–3: Sudden appearance of fever, headache, muscle pain and weakness, dry cough, sore throat and sometimes a stuffy nose.
• Day 4: Fever and muscle aches decrease. Hoarse, dry or sore throat, cough and possible mild chest discomfort become more noticeable. You may feel tired or flat.
• Day 8: Symptoms decrease. Cough and tiredness may last one to two weeks or more.

What about flu complications?

In some cases of the flu, severe illness and complications (such as pneumonia and bronchitis) can develop. This can result in hospitalisation and even death.

The flu can also make some existing medical conditions worse.

In Victoria, flu vaccination is free under the National Immunisation Program for people with a higher risk of severe complications associated with the flu:

• Aboriginal and Torres Strait Islander people aged 6 months and over
• Children aged 6 months to under 5 years
• Pregnant women at any stage of pregnancy
• People aged 65 years or over
• People aged 6 months or over who have medical conditions that mean they have a higher risk of getting serious disease:
  • cardiac disease
  • chronic respiratory conditions
  • immunocompromising conditions
  • haematological disorders
  • chronic metabolic disorder
  • chronic kidney disease
  • chronic neurological condition
  • long term aspirin therapy in children aged 5 to 10 years.

Speak to your immunisation provider to see if you meet the eligibility for free flu vaccine.

Yearly influenza vaccination is also recommended for all other people aged 6 months and over. Talk to your immunisation provider about getting vaccinated.

People not eligible for free flu vaccination under the NIP can purchase the flu vaccine from their immunisation provider.

How can I avoid getting the flu?

Getting a flu vaccine every year is recommended for everyone aged 6 months or older.

While not 100% effective, the flu vaccine provides a high level of protection and can reduce symptoms in those still getting sick.

The flu vaccine can be co-administered (that is, given on the same day, one after the other) with other vaccines. This includes whooping cough, respiratory syncytial virus (RSV), pneumococcal and COVID-19 vaccines.

Speak to your immunisation provider for advice about COVID-19 and flu vaccines for children aged 6 months to less than 5 years.

Wearing a face mask and practicing good hand hygiene can help to reduce your chances of catching the flu or passing it on to others.

I think I have the flu – should I see a doctor?

Anyone at a higher risk of serious illness with flu-like symptoms should see their doctor as soon as possible.

Most people who are generally healthy won’t need to see their doctor for the flu. As symptoms of the flu are similar to COVID-19, talk to your doctor about testing for COVID-19 infection.

If you have the flu, try to rest, maintain a good fluid intake, and manage your symptoms. This will help you recover and prevent dehydration. Your immune system will fight the infection and symptoms will usually clear up on their own.

If you do need to see a GP for your symptoms, make sure you call ahead first so they can make sure there’s no one in an at-risk group around when you have your appointment.

When to seek medical attention

See your doctor if you have any concerns or are in a high-risk group for severe infection. Seek immediate medical attention if you experience any of the following symptoms:

• difficulty breathing
• chest pain
• sudden dizziness
• confusion
• severe vomiting
• fever with a rash.

How can I avoid giving the flu to other people?

It is important we all play our part in helping fight the flu and to protect our health system.

Aside from getting your flu shot, follow these 3 simple steps to stop the spread of the flu:

Step 1 - Cough or sneeze into your elbow

If you feel a cough or sneeze is coming on, make sure to cough or sneeze into your elbow. It’s a part of your body less likely to touch other surfaces and will help stop the spread of nasty germs.

Step 2 - Wash your hands thoroughly and regularly

• Our hands are one of the top spreaders of viruses. The flu virus is carried in almost invisible droplets from saliva, sneezes, coughs, and runny noses.
• Flu viruses can live on surfaces such as lift buttons or handrails for up to 48 hours and are spread when people touch an infected surface.
• Wash your hands thoroughly and often with soap and water for at least 20 seconds – especially if you have been in a public place, or after blowing your nose, coughing, sneezing or using the toilet. If soap and water are not readily available, use a hand sanitiser containing at least 60% alcohol.

Step 3 - Rest and recover at home

• If you are sick, rest at home and drink plenty of fluids. Avoid going out, even to the supermarket, where you risk spreading the virus to others. Wear a mask if you need to go out.
• If you start to experience more serious symptoms, seek medical attention.

Looking after yourself when you have the flu

The best things you can do to look after yourself when you have the flu are:

• Rest – you will probably feel very weak and tired until your temperature returns to normal (about 3 days). Rest provides comfort and allows your body to use its energy to fight the infection.
• Stay at home – stay away from work, school and any places where you may have contact with others, especially while you are contagious. The period during which adults are contagious is usually around 3–5 days from when the first symptoms appear, and up to 7 days in younger children.
• Drink plenty of fluids – extra fluids are needed to replace those lost because of the fever (through sweating). If your urine is dark, you need to drink more. Try to drink a glass of fluids, such as water, every hour while you are awake.

What medications should I take for the flu?

The flu is a viral infection so antibiotics won’t help and should not be taken.

Antiviral medications, if started in the first 2 days after symptoms start, can shorten the length of your illness. These need to be prescribed by your doctor.

Decongestants and simple pain relievers can help you feel better while your body's immune system fights off the infection.

Tips for buying over-the-counter medications

Follow these tips for buying over-the-counter medication for the flu:

• Buy a remedy that treats only one symptom – this way you are not taking any substances you do not need, or that may trigger an adverse reaction.
• Read the medication label and check:
  • whether the active ingredient treats your symptoms
  • possible side effects
  • possible interactions with any medications, (including prescription and over-the-counter, medicines (such as vitamins and mineral supplements and herbal medicines)
  • whether the medication is safe for you to take if you have any health conditions
• If you are unsure if a medication is suitable for you to take, or if you have any other questions, talk to your doctor or pharmacist. They can suggest a medication that is appropriate and safe for you to take.

Useful tips to aid recovery from the flu

Other useful flu recovery tips include:

• Take simple pain-relieving medication (such as paracetamol or ibuprofen), as directed on the packet, to ease muscle pain and bring down your fever (unless your doctor says otherwise).
• Never give any medications that contain aspirin to children (under 12 years) unless advised by a doctor. The combination of the flu and aspirin in this age group has been known to cause Reye’s syndrome – a very serious condition affecting the nervous system and liver.
• Antibiotics are not effective against the flu because influenza is a virus, and antibiotics fight bacteria. However, your doctor may prescribe them if you develop a bacterial infection on top of the flu.
• Gargle with a glass of warm water to ease a sore throat. Sucking on sugar-free lollies or lozenges also helps.
• A hot water bottle or heating pad may help relieve muscle pain. A warm bath may also be soothing.
• Use saline nose drops or spray to help soothe or clear a stuffy nose. These decongestants help shrink swollen blood vessels in the nose. Talk to your doctor or pharmacist about which medication will be the best for you.
• Do not smoke – this will irritate your damaged airways.
• Try warm, moist air inhalation. Boil a kettle, wait a minute for the water to slightly cool, and carefully empty the hot water into a bowl. Place the bowl on a steady surface, such as a table. Put a towel over your head and inhale the warm air in the bowl for up to 20 minutes. There is no need to add anything to the water. Be careful not to touch the water and keep it out of reach of children.
• Ask for help if you live alone or care for others. You may need support until you feel better.
• Remember, if you buy medicine at the pharmacy to treat your symptoms (over-the-counter medications), check with the pharmacist to see which one is right for you. Let them know if you have a chronic illness or are taking any other medication.

Where to get help

• In an emergency, always call triple zero (000)
• Your GP (doctor)
• NURSE-ON-CALL Tel. 1300 60 60 24 – for expert health information and advice (24 hours, 7 days)
• Your pharmacist