Cold vs Flu: How to Tell the Difference and Treat Each in Australia
At a Glance
Colds come on gradually with mainly upper respiratory symptoms. The flu hits suddenly with high fever, severe body aches, and exhaustion. Most people can manage both at home with rest, fluids, and OTC symptom relief — but the flu carries a higher risk of serious complications.
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
| Symptom | Common Cold | Influenza (Flu) |
|---|---|---|
| Onset | Gradual — over 1-3 days | Sudden — within hours |
| Fever | Rare or low-grade | Common, often high (38-40 degrees C) |
| Headache | Uncommon | Common and can be severe |
| Body aches | Mild | Severe — 'hit by a truck' feeling |
| Fatigue | Mild — can still function | Severe — can last 2-3 weeks |
| Runny/stuffy nose | Very common — main symptom | Sometimes |
| Sneezing | Common | Uncommon |
| Sore throat | Common — often first symptom | Sometimes |
| Cough | Mild to moderate | Common, can be severe and dry |
| Chills and sweats | Uncommon | Common |
The Quick Test
Could you go to work today if you really had to? If 'yes, but I would rather not' — probably a cold. If 'absolutely not, I cannot get out of bed' — more likely the flu.
How Long Does Each Last?
| Common Cold | Influenza | |
|---|---|---|
| Total duration | 7-10 days | 1-2 weeks (fatigue may linger 2-3 weeks) |
| Worst symptoms | Days 2-3 | Days 1-4 |
| Contagious period | 1-2 days before to ~5 days after | 1 day before to 5-7 days after |
| Time off work | Usually 1-3 days | Often 5-7 days or more |
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.
Panadol Rapid (Paracetamol 500mg)
Fast-acting pain relief. Gentle on the stomach. Suitable for headaches, fever, and general aches.
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.
Sudafed Nasal Decongestant
Effective relief from nasal and sinus congestion caused by cold, flu, or allergies.
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.
Codral Cold & Flu Day & Night
Day and night formula for relief from cold and flu symptoms including blocked nose, headache, and fever.
Demazin Original Cold and Flu Relief Day Night Tablets
Relief for cold and flu symptoms including runny/stuffy nose, sinus pain, headache, and fever.
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.
Nurofen (Ibuprofen 200mg)
Fast, effective pain relief with anti-inflammatory action. Ideal for period pain, back pain, and inflammation.
Antiviral medication (prescription only)
Oseltamivir (Tamiflu) 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.
Aspirin Warning
Never give aspirin to children or teenagers with flu symptoms. Aspirin use during a viral illness in young people has been linked to Reye's syndrome, a rare but serious condition affecting the brain and liver.
OTC Treatment Comparison
| Treatment | Cold? | Flu? | Notes |
|---|---|---|---|
| Paracetamol | Yes — mild aches, fever | Yes — essential for fever | Do not exceed 4g/day. Check for hidden paracetamol in combos. |
| Ibuprofen | Yes — sinus pain | Yes — body aches, fever | Take with food. Avoid with stomach ulcers. |
| Pseudoephedrine | Yes — blocked nose | Sometimes | Behind counter, show ID. |
| Combo tablets (Codral, Demazin) | Yes — multiple symptoms | Yes | Check ingredients to avoid doubling paracetamol. |
| Throat lozenges/gargle | Yes — sore throat | Sometimes | Temporary relief. |
| Antiviral (Tamiflu) | No | Yes — prescription, within 48h | High-risk groups mainly. |
When to See a Doctor
Seek Urgent Medical Attention If
- •Difficulty breathing or shortness of breath
- •Persistent chest pain or pressure
- •Confusion, dizziness, or difficulty staying conscious
- •Severe vomiting preventing fluid intake
- •Fever above 40 degrees C not responding to paracetamol or ibuprofen
- •Symptoms that improve then suddenly worsen (may indicate secondary infection)
- •Symptoms lasting more than 10 days (cold) or 2 weeks (flu)
High-risk groups
- •Adults aged 65 and over
- •Pregnant women
- •Children under 5 years
- •Aboriginal and Torres Strait Islander people
- •People with chronic conditions (asthma, diabetes, heart disease, kidney disease)
Prevention
Flu vaccination
The annual flu vaccine is the single most effective prevention. Available from April each year, free under the National Immunisation Program for high-risk groups. Everyone else can get it at a pharmacy or GP for around $15-$30.
Everyday prevention
- •Wash hands frequently with soap for at least 20 seconds
- •Avoid touching your face
- •Stay home when sick — most contagious in first 2-3 days
- •Cover coughs and sneezes with your elbow
- •Clean frequently touched surfaces
Frequently Asked Questions
Should I take antibiotics for a cold or flu?
No. Both are caused by viruses; antibiotics treat bacterial infections only. Antibiotics are only appropriate if your GP diagnoses a secondary bacterial infection such as sinusitis or pneumonia.
How can I tell if it is COVID-19?
COVID-19 shares many symptoms with both colds and flu. If unsure, take a rapid antigen test (RAT). These are widely available at pharmacies and supermarkets across Australia.
When is flu season in Australia?
Typically June to September, peaking in August. Get the flu vaccine from April onwards so immunity is established before peak season.
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.
Disclaimer
This article is for informational purposes only and does not constitute medical advice. Always read the label and follow the directions for use. If symptoms persist, talk to your health professional. See your pharmacist or GP for advice tailored to your situation.
Our Recommendation
If your symptoms came on suddenly with a high fever and severe body aches, it is most likely influenza. Treat with rest, fluids, and paracetamol or ibuprofen. See a GP within 48 hours if you are in a high-risk group. If symptoms are mainly above the neck — runny nose, sneezing, mild sore throat — it is probably a cold. Treat the symptoms that bother you most.
