Flu in Children: Symptoms, Recovery and When to Worry
In short: Flu in children usually starts suddenly with a high fever, body aches, headache and a dry cough, and most children recover at home within 5 to 7 days. The things that matter are watching breathing, fluids and alertness, keeping your child home until they have been fever-free for 24 hours without medicine, and knowing which signs need a doctor the same day.
Key takeaways
Influenza is caused by the influenza A and B viruses and spreads through droplets and hands, so school and taska clusters are common in Malaysia.
Flu tends to hit harder and faster than a cold: high fever, aches and tiredness often appear within a few hours.
Fever from flu usually lasts 2 to 4 days, while the cough and tiredness can hang on for one to two weeks.
Children under 5, especially under 2, and children with asthma, heart, kidney or neurological conditions are more likely to have complications.
A yearly flu vaccine is recommended for children from 6 months of age, and antibiotics do not treat influenza itself.
What does flu look like in children?
Flu usually arrives suddenly with a fever of 38.5°C or higher, chills, muscle aches, headache, sore throat and a dry cough, and the child looks and feels clearly unwell.
Parents often tell me their child was fine at breakfast and flat on the sofa by lunchtime. That sudden start is a useful clue; a cold creeps in over a day or two.
Common symptoms by age
Babies and toddlers: fever, fussiness, poor feeding, sleepiness, runny nose, cough, and sometimes vomiting or diarrhoea. They cannot tell you they ache, so they cry more or refuse to be put down.
Preschool children: fever, cough, sore throat, tummy pain, and complaints that their legs hurt.
School-age children and teenagers: similar to adults, with high fever, headache, body aches, sore throat, dry cough and marked tiredness.
Could it be dengue instead?
In Malaysia, a sudden high fever with body aches can also be dengue, especially if there are cases in your area. Dengue usually has less cough and runny nose, and may bring pain behind the eyes, a rash or nausea. If the fever lasts more than two days and you are unsure, see a doctor, who may check a full blood count. Our guide to dengue warning signs in children explains what to watch for.
How long does flu last in children?
Most children have fever for 2 to 4 days and feel much better within a week, but a cough and low energy can last up to two weeks.
A typical course
Days 1 to 3: highest fever, aches, headache, poor appetite, lots of sleep.
Days 3 to 5: fever settles; cough and runny nose may become more noticeable.
Days 5 to 14: energy slowly returns; a dry cough often lingers, especially at night.
How long is a child with flu contagious?
Children can spread flu from about a day before symptoms start until around 7 days after, and young children may stay infectious for longer.
When can my child go back to school or taska?
Keep your child home until they have had no fever for at least 24 hours without paracetamol or ibuprofen, and they are well enough to take part in normal activities. A leftover cough on its own is not usually a reason to stay home once they are otherwise well, though your school may have its own rules during an outbreak.
How do I stop it spreading at home?
Teach coughing and sneezing into a tissue or elbow, then washing hands with soap.
Do not share cups, spoons or towels during the illness.
Wipe door handles, remote controls and tablets daily.
Keep the sick child away from newborns and vulnerable relatives where possible.
Which children are at higher risk of complications?
Children under 5, and especially under 2, are more likely to develop complications from flu, as are children with long-term conditions such as asthma, heart disease or neurological problems.
Higher-risk groups
Babies and children under 5 years old.
Children with asthma or other chronic lung disease.
Children with heart, kidney or neurological conditions, diabetes or a weakened immune system.
What complications can happen?
The most common are ear infections, sinus infections and pneumonia. Flu can also trigger an asthma attack, dehydration or febrile seizures in young children. Rarely, it inflames the muscles, heart or brain, which is why the red flags below matter.
How is flu treated in children?
Most children with flu need rest, fluids and fever relief at home; antiviral medicine is used for children who are very unwell or at higher risk, and works best when started early.
Does my child need antibiotics?
Not for flu itself. Antibiotics do not work on viruses, though a doctor may prescribe them for a bacterial complication such as pneumonia.
What about antiviral medicine?
Antiviral medicine for flu is usually recommended for children who are in hospital, who are very unwell, or who are in a higher-risk group, including children under 5. It works best when started within 48 hours of symptoms, though it can still help later in severe illness. Your doctor will decide whether it is needed and give the correct dose for your child's weight.
Fever medicine
Paracetamol or ibuprofen can make your child more comfortable. The goal is comfort, not a normal thermometer reading. Use the dose on the label for your child's age and weight, or ask your pharmacist. Never give aspirin to children, as it is linked to a rare but serious condition called Reye's syndrome. For more on handling fever, see our guide on fever in children.
When to see a doctor, and when not to worry
Most children with flu can be cared for at home, but difficulty breathing, signs of dehydration, unusual drowsiness or a fever that returns after improving need prompt medical attention.
Usually fine to manage at home
Fever for up to 3 days in a child over 6 months who perks up when the fever comes down.
Drinking enough to pass urine at least every 6 to 8 hours.
Body aches, headache and tiredness that improve day by day.
A dry cough that lingers for one to two weeks while energy returns.
Poor appetite for a few days, as long as fluids are going in.
Book an appointment soon
Fever lasting more than 3 days, or more than 2 days if dengue is possible.
Ear pain, ear discharge or pulling at the ear.
A cough still going strong after 2 to 3 weeks.
Your child has asthma, a heart condition or another long-term illness and has flu symptoms.
Your child is under 2 and you think it is flu, especially if symptoms started within the last 48 hours.
Fever and cough that improved and then came back.
See a doctor the same day
Any fever in a baby under 3 months old.
Fast breathing, working hard to breathe, ribs pulling in, or grunting.
Blue or grey lips or face.
Very drowsy, hard to wake, or not responding normally.
Signs of dehydration: no urine for 8 hours, dry mouth, no tears, sunken eyes.
A seizure, or severe leg pain with refusal to walk.
Chest pain, a stiff neck, or a rash that does not fade when pressed.
Persistent vomiting, or severe tummy pain with bleeding, which can point towards dengue.
What can I do at home to help my child recover?
Focus on fluids, rest and comfort, offer small drinks often, and treat fever only when it makes your child miserable.
Babies under 12 months
Keep breastfeeding or formula feeding; offer feeds more often and for shorter times.
Dress your baby in light cotton and keep the room comfortably cool.
Check nappies: fewer wet nappies is an early sign of dehydration.
Toddlers and preschool children
Offer water, diluted juice, soup or ice lollies every 15 to 30 minutes while awake.
Let them rest on the sofa with quiet play; they do not need to stay in bed.
Do not worry about solid food for a few days if they are drinking.
Honey can soothe a cough in children over 1 year, but never give honey to babies under 12 months.
What not to do
Do not give aspirin to anyone under 16.
Do not ask for antibiotics for uncomplicated flu.
Do not use over-the-counter cough and cold syrups in young children.
Do not sponge with cold water or alcohol; it makes children shiver and feel worse.
From Dr Nisa's clinic: When flu goes round the schools, I often see whole families come in one after another. The pattern I look for is how the child is between fever spikes. A child who is miserable at 39°C but sits up, drinks and chats once the paracetamol works is usually doing well. The child I worry about is the one who stays flat and uninterested even when the temperature comes down, or who is breathing fast while at rest. That is the moment to come in.
How can I protect my child from flu?
A yearly flu vaccine is the best single step, recommended for every child from 6 months of age, with good hand hygiene and staying home when sick as backup.
The flu vaccine
It is recommended once a year because the flu strains change each season.
Children under 9 having it for the first time need two doses at least four weeks apart.
In Malaysia it is not part of the routine national schedule for healthy children, so most families get it at a private clinic or hospital, although some states have offered free vaccination in schools during outbreaks.
You can read more about the routine schedule in our guide to child vaccinations in Malaysia.
Worried about flu in your child?
If your child's flu is not following the usual pattern, or they have a long-term condition, I am happy to see them. I am Dr Nisa Khalil, a consultant paediatrician with more than 18 years of experience, seeing children at ParkCity Medical Centre in Desa ParkCity, Kuala Lumpur.
Book an appointment or, for non-urgent questions, try an online eConsult. If your child shows any of the same-day warning signs above, go to your nearest emergency department.
You may also find these helpful:
Frequently asked questions
How can I tell if my child has flu or a cold?
Flu usually starts suddenly with a high fever, body aches, headache and tiredness, and your child looks clearly unwell. A cold starts gradually, usually with a runny or blocked nose and sneezing, and fever is mild or absent. Children with a cold often keep playing; children with flu usually do not. Only a test can confirm flu, so if you are unsure and your child is very unwell or in a higher-risk group, see a doctor.
How long does a fever last with flu in children?
Fever from flu typically lasts 2 to 4 days, sometimes up to 5. It often runs high, around 39 to 40°C, and may come and go through the day. If the fever lasts beyond 3 days, keeps rising, or disappears and then returns after a day or two, have your child checked, because this can point to a complication such as pneumonia or an ear infection.
Can my child go to school with a cough after flu?
Usually yes, once they have been fever-free for 24 hours without fever medicine and feel well enough to join in. A dry cough can linger for one to two weeks after flu and does not by itself mean your child is still highly infectious. Teach them to cough into their elbow and wash hands often. During an outbreak, follow any specific advice from the school or local health office.
Is flu dangerous for babies?
Babies and children under 2 are more likely than older children to develop complications such as pneumonia, dehydration and febrile seizures, and some need hospital care. Any fever in a baby under 3 months needs a doctor the same day. For older babies, watch feeding, wet nappies, breathing and alertness closely, and see a doctor early rather than waiting it out.
Does my child need Tamiflu for the flu?
Not always. Antiviral medicine such as oseltamivir is recommended for children who are very unwell, in hospital, or in a higher-risk group, including those under 5 and children with asthma or chronic illness. It works best when started within 48 hours of symptoms. Healthy older children with mild flu usually recover well without it. Your doctor will decide and prescribe the right dose.
When should my child get the flu vaccine?
Any time from 6 months of age, ideally once a year. Flu circulates through most of the year in Malaysia, so there is no wrong month. Children under 9 having it for the first time need two doses at least four weeks apart. Ask your paediatrician which vaccine is available.
Medically reviewed by Dr Nisa Khalil on 2 November 2026. This article is general information and does not replace a consultation with your own doctor.
References
World Health Organization. Influenza (seasonal): fact sheet. who.int
Centers for Disease Control and Prevention. Flu and children: symptoms, emergency warning signs and treatment. cdc.gov
American Academy of Pediatrics Committee on Infectious Diseases. Recommendations for prevention and control of influenza in children, 2025 to 2026. Pediatrics. publications.aap.org
American Academy of Pediatrics. Flu: a guide for parents. HealthyChildren.org. healthychildren.org
NHS. Flu. nhs.uk
Worried about your child?
Book an appointment with Dr Nisa Khalil for calm, evidence-based paediatric care when your child is unwell.
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