What Are the Symptoms of Flu in Adults and Children? A GP's Guide for Winter 2026

What Are the Symptoms of Flu in Adults and Children?

Influenza (flu) and the common cold share some symptoms, but they are different illnesses that carry different risks. Understanding the difference helps families in Wollongong decide when to rest at home and when to see a GP.

The short answer: Flu comes on suddenly and typically causes fever, body aches, chills, fatigue, and sometimes breathing difficulty. A cold builds gradually and stays mostly in the nose and throat.

Flu Symptoms: What to Look For

The most reliable indicator of flu over a cold is how fast it hits. Most people with flu describe going from fine to unwell within a few hours.

Who Is Most at Risk of Serious Flu Complications?

According to the Australian Department of Health, the following groups face higher risk of serious illness from influenza:

• Children under 5, particularly those under 2
• Adults aged 65 and over
• Pregnant women (at any stage of pregnancy)
• Aboriginal and Torres Strait Islander people
• People with chronic health conditions, including heart disease, diabetes, kidney disease, and respiratory conditions

Children can deteriorate quickly. If a child has had a fever for more than 48 hours, is breathing harder than usual, or is becoming difficult to rouse, seek same-day medical attention.

Source: Australian Government Department of Health. Influenza (flu). health.gov.au

When Should You See a GP for Flu?

Rest, fluids, and time resolve many flu episodes. But a GP appointment is appropriate when:

• Symptoms are getting worse rather than improving after 48 hours
• Breathing becomes laboured or painful
• A fever is persistent or very high
• You are in a higher-risk group (see above)
• You are unsure whether it is flu, COVID-19, or another respiratory illness
• A child is unusually sleepy, not drinking fluids, or not responding normally

You do not need to wait until something feels like an emergency. Seeing a GP early often means faster support and clearer guidance. Book a GP appointment at Embrace Medical.

Does the Flu Vaccine Prevent Flu?

The flu vaccine reduces the risk of influenza infection and lowers the likelihood of serious illness, particularly for higher-risk groups. It does not guarantee protection against all strains, as the vaccine composition is updated each year to match circulating strains.

Annual vaccination is recommended for everyone aged 6 months and over. It is free under the National Immunisation Program for eligible groups including adults 65+, pregnant women, Aboriginal and Torres Strait Islander people, and those with certain medical conditions.

Talk to a GP about whether the flu vaccine is appropriate for your family this winter.

Frequently Asked Questions

How long does flu last in adults? 

Most otherwise healthy adults recover from flu within 7 to 10 days. Fatigue may linger for several weeks, particularly after severe illness.

Can you have flu without a fever? 

Yes, though it is less common. Some adults — particularly older people — may not mount a typical fever response even when significantly unwell.

Is it flu or COVID-19?
The symptoms overlap considerably. Testing is the only reliable way to distinguish between them. A GP can advise on appropriate testing.

When is flu season in Australia?
The Australian flu season typically runs from June through September, peaking in July and August.

Reviewed by the GPs at Embrace Medical on Crown, Wollongong. Information is general in nature and does not replace personalised medical advice. If you are concerned about your health or your child's health, please consult a GP.

Sources: health.gov.au/topics/flu; healthdirect.gov.au/cold-versus-flu