Cold vs Flu in Children: How to Tell the Difference

On this page

• What is the difference between a cold and the flu?
• Cold or flu — the key differences
• What are the symptoms of a cold in children?
• What are the flu symptoms in kids?
• Does a cold or the flu cause a fever?
• How long does a cold last compared with the flu?
• Is it contagious, and for how long?
• Could it be COVID instead?
• How to help a child with a cold or flu at home
• When to see a doctor
• FAQs

What is the difference between a cold and the flu?

A cold and the flu (influenza) are both viral infections of the airways, and in the first day or two they can look almost identical. The difference is in how they start and how hard they hit. A common cold usually creeps in over a day or two and stays fairly mild — the main action is in the nose and throat. The flu tends to arrive suddenly and makes a child feel properly unwell all over, with a higher fever, aches and deep tiredness. As a rough guide: if your child is still up and playing between blowing their nose, it is more likely a cold; if they are flattened, feverish and achy, it is more likely the flu.

Cold or flu — the key differences

Symptoms overlap, so no single sign is proof either way. But the overall pattern usually points one way or the other. Here is how a cold, the flu and COVID-19 tend to compare in children:

	Common cold	Flu (influenza)	COVID-19
How it starts	Gradual, over a day or two	Sudden, often within hours	Gradual or sudden — varies
Fever	Mild or none	Common, often higher	Common
Body aches & tiredness	Mild	Common and can be severe	Common
Runny or blocked nose	Very common	Sometimes	Sometimes
Cough	Mild, tickly	Common, can be chesty	Common
How long	Around 1 week	1–2 weeks, cough can linger	Days to a couple of weeks
How to be sure	Usually no test needed	A doctor can test if needed	A rapid antigen test can help

What are the symptoms of a cold in children?

A cold is the most common childhood illness — young children can have several each year, especially once they start childcare or school. Symptoms usually build up gradually and centre on the nose and throat:

• A runny or blocked nose, often with clear or coloured mucus
• Sneezing and a scratchy or sore throat
• A mild cough
• Watery eyes
• Sometimes a mild temperature, but many children have none

Children with a cold are usually still eating, playing and sleeping reasonably well. Colds clear up on their own with rest, fluids and a bit of comfort at home.

What are the flu symptoms in kids?

The flu tends to come on quickly and makes a child feel much more unwell than a cold. Common flu symptoms in children include:

• A sudden fever, often higher than with a cold
• Aching muscles, and generally feeling sore all over
• Headache
• Marked tiredness and low energy — wanting to lie down rather than play
• A dry or chesty cough and a sore throat
• Chills or shivering
• In younger children, sometimes tummy upset such as vomiting or diarrhoea

Because the flu hits harder, children often need a few days of rest before they start to bounce back. If your child has a temperature, a forehead thermometer makes it easy to keep an eye on it — see our guide to when a fever is dangerous.

Does a cold or the flu cause a fever?

Both can, but the pattern differs. A cold usually causes only a mild temperature, or none at all — a high fever is uncommon with a straightforward cold. The flu, on the other hand, often brings a higher, more sudden fever along with chills and aches. A fever is the body’s normal response to fighting a virus and, on its own, is not dangerous. What matters more is how your child is coping: a child who is drinking, alert between rests and settling is usually managing well. For how to read a temperature by age and when to act, see our guides to toddler fever and baby temperature.

How long does a cold last compared with the flu?

A common cold usually lasts about a week, though a mild cough or runny nose can hang on a little longer. The flu tends to last longer — most children start to feel better after about a week, but the tiredness and cough can drag on for up to two weeks or more. With both, symptoms should be steadily improving after the first few days. A child who is getting worse rather than better, or who seems to recover and then goes downhill again, should be seen by a doctor, as a second infection can sometimes follow a cold or flu.

Is it contagious, and for how long?

Yes — both colds and the flu are contagious and spread easily through droplets from coughing and sneezing, and from hands and shared surfaces. Children are usually most infectious in the first few days, often starting the day before symptoms appear. As a general rule, keep your child home from school or childcare while they are unwell, feverish or too tired to take part, and let them return once they are recovering and fever-free. Regular hand-washing and keeping hand sanitiser handy help stop it spreading through the household.

Could it be COVID instead?

It can be hard to tell COVID-19 apart from a cold or the flu on symptoms alone, because they overlap so much. If you want to know, the simplest step is a rapid antigen test (RAT), which you can do at home. Testing is worth considering if your child is unwell and will be around people at higher risk, or if your school, childcare or workplace asks for it. Whatever the result, the home care is much the same — rest, fluids and comfort — and the same “when to see a doctor” signs below apply. Follow current Australian health advice on testing and isolation, which can change over time.

How to help a child with a cold or flu at home

Most colds and flu are managed at home while the illness runs its course. The aim is comfort and rest:

• Offer plenty of fluids in small, frequent sips to keep them hydrated
• Let them rest as much as they need — sleep helps recovery
• Keep the room comfortable and dress them in light layers
• For a blocked nose, saline drops or spray can help younger children who cannot blow their nose
• Ask your pharmacist or GP before giving any medicine; do not give over-the-counter cough and cold medicines to young children unless a doctor advises it

Paracetamol or ibuprofen can be used for a child who is miserable with fever or aches — follow the dosing for your child’s age and weight, and check with your pharmacist or GP if you are unsure. A forehead thermometer helps you keep an eye on a temperature, and if your child is uncomfortable a FeverMates cooling patch can add a little comfort (it provides a cooling sensation only — it does not lower a temperature or treat the infection). There is no home cure that shortens a cold or flu; time, rest and fluids do the work. If your child is unwell and you want to check whether it is COVID, a rapid antigen test is a simple option.

When to see a doctor

Most children with a cold or the flu do not need to see a doctor. Seek medical advice if your child:

• Is a baby under 3 months with any fever, or under 6 months and unwell
• Is having trouble breathing, breathing fast, or wheezing
• Is very drowsy, floppy, hard to wake or unusually irritable
• Is not drinking and has signs of dehydration (few wet nappies, dry mouth, no tears)
• Has a fever that lasts more than a couple of days, or seems to recover and then gets worse again
• Has a rash that does not fade when you press on it

Call 000 immediately if your child is struggling to breathe, turns blue or grey, is unresponsive, or you are seriously worried. For advice any time, call healthdirect on 1800 022 222, or 13 HEALTH on 13 43 25 84 in Queensland. A flu vaccine is available each year and is recommended for most children — ask your GP or child health nurse about what suits your family.

Frequently asked questions

How can I tell if my child has a cold or the flu?

Look at how it started and how unwell they are. A cold comes on slowly and stays mild, mostly a runny nose and mild cough. The flu comes on suddenly with a higher fever, body aches and deep tiredness. If your child is flattened and feverish, it is more likely the flu.

Is the flu worse than a cold in children?

Usually yes. The flu tends to make children feel much more unwell, with a higher fever, aches and tiredness, and it lasts longer. Most children still recover at home, but the flu is more likely to knock them around and, in some cases, lead to complications, so keep a closer eye on them.

How long is my child contagious with a cold or flu?

Children are usually most infectious in the first few days, often from the day before symptoms start. A good rule is to keep them home while they are unwell, feverish or very tired, and let them return to school or childcare once they are recovering and fever-free.

Should I test my child for COVID?

A rapid antigen test is a simple way to check if you want to know, especially if your child will be around people at higher risk or your school or workplace asks for it. Either way, the home care is the same, and follow current Australian advice on testing and isolation.

Do antibiotics help a cold or the flu?

No. Colds and the flu are caused by viruses, and antibiotics only work on bacteria, so they will not help and are not usually prescribed. Care is about comfort and rest. Your doctor will advise if antiviral medicine is appropriate for the flu, or antibiotics for a separate bacterial infection.

Related reading

Sorting out a winter illness? See our guides to croup in children, toddler fever and baby temperature, plus other common childhood illnesses, and browse the full FeverMates range in our online shop.

Sources

Royal Children’s Hospital Melbourne; healthdirect Australia; Raising Children Network; Better Health Channel (Victoria); Australian Government Department of Health. Reviewed against Australian guidance.

This article is general information only and is not a substitute for medical advice. If you are worried about your child’s breathing or health, see your GP, call healthdirect on 1800 022 222, or in an emergency call 000.