Cold vs Flu in Australia: Symptoms & Treatment (2026)

A cold comes on gradually over one to two days and mainly affects the nose and throat — you rarely get a significant fever. The flu hits suddenly, often within hours, and typically causes a high fever (38-40 degrees C), severe body aches, and exhaustion. If you feel like you have been knocked flat, it is more likely the flu. In Australia, flu season runs from roughly May to September and peaks in August.

What Are Colds and Flu?

Both the common cold and influenza are respiratory infections caused by viruses — but different virus families. The common cold is most often caused by rhinoviruses, while the flu is caused by influenza A or B viruses. Because both are viral, antibiotics will not help with either condition.

Cold vs Flu Symptom Comparison

How Long Does Each Last?

Day-by-Day Timeline: Cold vs Flu

Knowing roughly where you are in the illness can reassure you that things are tracking normally — or flag when something is not. The progression below is a general guide; everyone recovers at their own pace.

Cold vs Flu vs COVID-19

COVID-19 shares many symptoms with both colds and the flu, which makes it hard to tell them apart on symptoms alone. The table below shows how often each symptom appears, but the only reliable way to confirm COVID-19 is a rapid antigen test (RAT) or PCR test. RATs are widely available at pharmacies and supermarkets across Australia.

How to Treat a Cold

There is no cure for the common cold. Treatment focuses on relieving the specific symptoms that bother you most.

Pain and fever relief

Paracetamol is the first choice for mild headaches, sore throats, and low-grade fever. Ibuprofen is an alternative if you also have sinus pain or inflammation.

Nasal congestion

Pseudoephedrine-based decongestants (behind the counter — show ID at pharmacy) remain the most effective option. Products containing phenylephrine on the open shelf have been shown in recent studies to be no more effective than placebo when taken orally.

Multi-symptom relief

If you have several symptoms at once, a combination cold and flu tablet can be convenient. Be careful not to take extra paracetamol on top — many Australians accidentally exceed the safe daily dose this way.

How to Treat the Flu

The same OTC products used for colds also apply, but treatment is more aggressive because the flu is more severe.

Fever and pain management

Controlling fever is a priority with the flu. Paracetamol and ibuprofen are both effective. Some GPs suggest alternating between the two for high or persistent fever — but only on the advice of a pharmacist or doctor.

Antiviral medication (prescription only)

Oseltamivir (Tamiflu) is an antiviral used to treat influenza. It can reduce flu duration by about one day — but only if started within 48 hours of symptoms. Your GP is most likely to prescribe it for high-risk groups: over 65, pregnant, chronic conditions, or immunocompromised. In Australia, flu antivirals are not subsidised on the Pharmaceutical Benefits Scheme (PBS), so oseltamivir is dispensed on private prescription at your own cost. Talk to your GP about whether it is suitable for you.

OTC Treatment Comparison

When to See a Doctor

High-risk groups

• radio_button_uncheckedAdults aged 65 and over
• radio_button_uncheckedPregnant women
• radio_button_uncheckedChildren under 5 years
• radio_button_uncheckedAboriginal and Torres Strait Islander people
• radio_button_uncheckedPeople with chronic conditions (asthma, diabetes, heart disease, kidney disease)

Prevention

Flu vaccination

The annual flu vaccine helps prevent influenza and is the single most effective protection. It is usually available from April each year, ahead of the May-to-September flu season, and is free under the National Immunisation Program (NIP) for eligible groups — including over 65s, pregnant women, children aged 6 months to under 5 years, Aboriginal and Torres Strait Islander people, and those with certain chronic conditions. Everyone else can get it at a pharmacy or GP, typically for around $20-$30 (price varies by provider).

Everyday prevention

• radio_button_uncheckedWash hands frequently with soap for at least 20 seconds
• radio_button_uncheckedAvoid touching your face
• radio_button_uncheckedStay home when sick — most contagious in first 2-3 days
• radio_button_uncheckedCover coughs and sneezes with your elbow
• radio_button_uncheckedClean frequently touched surfaces

Frequently Asked Questions

How can I tell if I have the flu or just a cold?

Run through three quick questions. Did it come on fast (hours) or slowly (a day or two)? Do you have a high fever and heavy body aches, or mainly a stuffy nose and scratchy throat? Could you still get through a work day if you had to? Fast onset, high fever, severe aches, and being unable to function point to the flu. A slow build with mostly above-the-neck symptoms points to a cold.

What are the stages of a cold?

A cold usually moves through three stages. Days 1-2: a scratchy throat and early sniffles as symptoms set in. Days 3-4: peak symptoms, including a blocked or runny nose, sneezing, and a mild cough. Days 5-10: gradual recovery, though a light cough can linger after everything else clears. Most colds resolve within 7-10 days.

What is the worst day of a cold?

For most people, a cold feels worst around days 2-3, when congestion, sneezing, and a sore throat tend to peak. After that, symptoms usually start to ease. With the flu, the first 1-3 days are typically the most severe.

How long does the flu last in Australia?

The flu generally lasts 1-2 weeks. Fever and body aches are usually worst in the first few days and settle within about a week, but tiredness and a lingering cough can hang around for two to three weeks. If you are not improving after a week, or you get better then suddenly worse, see your GP.

Cold vs flu vs COVID — what is the difference?

All three are respiratory infections with overlapping symptoms. Colds are mild and gradual; the flu is sudden and severe with high fever and body aches; COVID-19 can resemble either and may include loss of taste or smell. Because symptoms overlap so much, a rapid antigen test (RAT) is the only reliable way to confirm COVID-19 at home.

Do I need antibiotics for a cold or the flu?

No. Both are caused by viruses, and antibiotics only work against bacterial infections. Taking antibiotics for a cold or flu will not help and contributes to antibiotic resistance. Antibiotics are only appropriate if your GP diagnoses a secondary bacterial infection such as sinusitis or pneumonia.

When should I see a doctor for flu symptoms in Australia?

See your GP within 48 hours of symptoms starting if you are in a high-risk group (over 65, pregnant, very young children, Aboriginal and Torres Strait Islander people, or those with chronic conditions), as antiviral treatment may help. Seek urgent care for any red flags: trouble breathing, chest pain, confusion, an inability to keep fluids down, a fever above 40 degrees C that will not come down, or symptoms that improve then suddenly worsen.

Is the flu vaccine free in Australia?

The flu vaccine is free under the National Immunisation Program (NIP) for eligible groups, including over 65s, pregnant women, children aged 6 months to under 5 years, Aboriginal and Torres Strait Islander people, and people with certain chronic conditions. Everyone else can still get vaccinated at a pharmacy or GP, typically for around $20-$30, with the price varying by provider.

When is flu season in Australia?

Flu season in Australia typically runs from May to September and peaks in August. Get the flu vaccine from April onwards so your immunity is established before the peak.

Can I exercise with a cold or flu?

Use the 'neck check': symptoms above the neck only (runny nose, sneezing) — gentle exercise is fine. Symptoms below the neck (chest congestion, body aches, fever) — rest. Never exercise with the flu.

Is it 'feed a cold, starve a fever'?

Not supported by evidence. Whether you have a cold or flu, your body needs fuel and hydration. Eat what you can tolerate and prioritise fluids.