Flu in Kids: Symptoms, Tamiflu and When to Worry
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Flu in Kids: Symptoms, Tamiflu and When to Worry

Quick answer: Flu in kids usually comes on suddenly, with a fever (often above 100.4°F / 38°C), chills, body aches, headache, sore throat, a dry cough and a stuffy or runny nose. Children are more likely than adults to also vomit or have diarrhea. Most healthy children recover at home in about a week with rest and fluids. Call your pediatrician within 24 hours of the first symptoms if your child is under 5 (especially under 2) or has a condition like asthma, because prescription antiviral medicine such as oseltamivir (Tamiflu) works best when started within the first 2 days. Go to the ER for trouble breathing, bluish lips, signs of dehydration, a seizure, or a fever that gets better and then comes back.

What is the flu, and how is it different from a cold?

Influenza (the flu) is a contagious respiratory infection caused by influenza viruses. It spreads through droplets when someone coughs, sneezes or talks, and by touching contaminated hands and surfaces.

A cold tends to creep in with a low-grade fever, a runny nose and a little coughing. The flu is different: it usually hits fast, and children feel much sicker, achier and more miserable. A child who was playing in the morning may be in bed with a high fever and body aches by the afternoon. For a side-by-side comparison, see our guide to cold vs. flu vs. RSV vs. COVID in kids.

Flu is not a minor illness for children. The American Academy of Pediatrics (AAP) called the 2025–26 season another high-severity season for kids, with 190 pediatric flu deaths reported so far, a number expected to rise as late reports come in. Historically, about 85% of children who die from flu were not vaccinated.

Flu symptoms in kids

According to the AAP and CDC, common flu symptoms in children include:

  • Sudden fever, usually above 100.4°F (38°C). Not everyone with flu has a fever.
  • Chills, headache and body aches, and being far more tired than usual
  • Sore throat and a dry, hacking cough
  • Stuffy or runny nose
  • Vomiting or diarrhea, which are more common in children than in adults

After the first few days, the fever and aches usually ease, and the sore throat, congestion and cough become the main complaints. The cough can linger after other symptoms are gone.

Babies and toddlers can’t tell you they ache, so watch how they’re acting, eating and drinking, and call your pediatrician if you’re unsure.

Which children are at higher risk?

Any child can get very sick from flu, but the CDC and AAP say these children are more likely to have serious complications:

  • Children younger than 5, and especially younger than 2
  • Babies under 6 months, who are too young for the flu vaccine
  • Children of any age with asthma or other lung disease, heart disease, diabetes, sickle cell disease, kidney disease, a weakened immune system, or a brain, nerve or muscle condition

Possible complications include ear and sinus infections, dehydration, and flare-ups of chronic conditions such as asthma. Fever from flu can also trigger febrile seizures in young children.

Flu treatment: do kids need Tamiflu?

Antibiotics don’t treat the flu, because it’s caused by a virus. Prescription antiviral medicines fight the flu virus itself. They can shorten the illness, make it milder and lower the risk of serious complications. In children ages 1 to 12, early treatment has also been linked to fewer ear infections needing antibiotics.

The CDC and AAP recommend antiviral treatment, started as early as possible, for:

  • Children who are hospitalized with confirmed or suspected flu
  • Children with severe, complicated or worsening illness
  • Children at higher risk of complications, including all children under 5 and children with conditions like asthma, diabetes, or heart or lung disease

For otherwise healthy children, the AAP says doctors may also offer antivirals if treatment can start within 48 hours of the first symptoms. Antivirals are used for both suspected and confirmed flu, and they need a prescription from your child’s doctor.

Timing matters. Antivirals work best when started within the first 2 days of illness. The CDC notes that higher-risk and very sick children can still benefit when treatment starts later, so don’t skip the call just because a couple of days have passed.

The flu antivirals used for children include:

  • Oseltamivir (Tamiflu or generic), a liquid or capsule taken by mouth. It’s the most commonly used option and can be given to babies. The most common side effects are nausea and vomiting.
  • Baloxavir (Xofluza), a single-dose pill for otherwise healthy children 5 to 11 years old and for everyone 12 and older. The AAP notes it is not recommended for hospitalized patients.
  • Zanamivir (Relenza), an inhaled powder for children 7 and older. It isn’t recommended for children with asthma or other lung disease.
  • Peramivir (Rapivab), given by IV, approved for children 6 months and older.

Your pediatrician will choose the medicine and the dose based on your child’s age, weight and health. Give it exactly as prescribed and finish the full course, even if your child feels better.

How to care for a child with the flu at home

  1. Rest. Let your child sleep and take it easy. Quiet activities on the couch are fine.
  2. Push fluids. Offer water, milk, oral rehydration solution, broth or ice pops often, in small sips if your child is nauseous. Drinking matters more than eating for the first few days.
  3. Treat discomfort, not the number. Acetaminophen or ibuprofen can ease fever and aches. Ask your pediatrician which medicine and dose is right for your child’s age and weight, and follow the package directions. The AAP notes that ibuprofen is for babies 6 months and older and shouldn’t be given to a child who is dehydrated or vomiting over and over.
  4. Never give aspirin (or products that contain it) to a child or teen with flu or flu-like symptoms. It’s linked to Reye syndrome, a rare but serious illness.
  5. Keep sick kids home. The CDC advises keeping children home until they’ve been fever-free for at least 24 hours without fever-reducing medicine. Check your school or daycare’s policy, too.

When to call the doctor

Call your pediatrician within 24 hours of the first flu symptoms if your child:

  • Is younger than 5, and especially younger than 2
  • Has asthma, a heart condition, diabetes, sickle cell disease, a weakened immune system, a neuromuscular condition or another chronic illness
  • Lives with or spends time with someone at high risk, such as a newborn or a family member who is pregnant or immunocompromised

Also call if your child:

  • Has a fever or cough that isn’t going away or isn’t getting better
  • Has ear pain, or pressure or pain in the face and head, which can mean an ear or sinus infection
  • Is drinking less than usual or making fewer wet diapers
  • Is younger than 3 months with any fever (see our guide on when to call the pediatrician about a fever)

When to go to the ER or call 911

Get emergency care right away if your child has any of these warning signs, which the CDC and AAP list for children with flu:

  • Fast breathing or trouble breathing
  • Bluish, gray or pale lips, face or nail beds
  • Ribs pulling in with each breath
  • Chest pain
  • Muscle pain so bad that your child refuses to walk
  • Signs of dehydration: no urine for 8 hours, a dry mouth, or no tears when crying
  • Not alert or not interacting when awake, or very hard to wake
  • A seizure
  • Fever above 104°F (40°C)
  • Any fever in a baby younger than 12 weeks
  • Fever or cough that gets better, then comes back or gets worse
  • A chronic condition, such as asthma, that is suddenly getting worse

This list isn’t complete. Trust your instincts: if your child seems seriously ill, get help. Call 911 if your child is struggling to breathe, turning blue, having a seizure or can’t be woken.

How long is flu contagious, and how do I keep it from spreading?

People with flu can spread it from about 1 day before symptoms start until 5 to 7 days after, according to the CDC. Young children and very sick people may stay contagious longer. To protect the rest of the family:

  • Wash hands often, especially after wiping noses and before eating.
  • Teach kids to cough and sneeze into a tissue or their elbow.
  • Don’t share cups, utensils or towels, and clean high-touch surfaces.
  • Keep sick siblings away from newborns and anyone at high risk when you can.

The best protection is a yearly flu vaccine for everyone 6 months and older. It’s not too late this season; see our flu shot for kids 2026–27 guide for who needs one dose or two.

Frequently Asked Questions

How long does the flu last in kids?

Most healthy children with flu feel better in about a week. Fever and body aches usually ease after the first few days, but a cough and tiredness can hang on longer. Call your pediatrician if your child isn’t improving.

Should my child take Tamiflu for the flu?

The CDC and AAP recommend antiviral medicine such as oseltamivir (Tamiflu) as early as possible for children under 5, children with conditions like asthma or diabetes, and any child who is very sick or hospitalized with flu. For healthy children, a pediatrician may offer it if it can start within 48 hours of symptoms. It requires a prescription.

What are the side effects of Tamiflu in kids?

The most common side effects of oseltamivir (Tamiflu) are nausea and vomiting. Tell your pediatrician if your child can’t keep it down or has any symptom that worries you.

Can kids get the flu even if they had a flu shot?

Yes, but the flu vaccine lowers the chance of getting sick and makes serious illness, hospitalization and death much less likely. If a vaccinated child gets flu symptoms, still call your pediatrician if they are under 5 or have a chronic condition.

When can my child go back to school after the flu?

The CDC advises keeping children home until they have been fever-free for at least 24 hours without using fever-reducing medicine. Your child should also be feeling well enough to take part in normal activities. Schools and daycares may have their own rules.

Do antibiotics help the flu?

No. The flu is caused by a virus, and antibiotics only work against bacteria. Your pediatrician may prescribe an antibiotic if a bacterial complication develops, such as an ear infection or pneumonia, or an antiviral medicine to fight the flu virus itself.

What flu symptoms in a child mean I should go to the ER?

Go to the ER for fast or hard breathing, bluish lips or face, ribs pulling in with breaths, chest pain, signs of dehydration, a seizure, being hard to wake, fever above 104°F, any fever in a baby under 12 weeks, or a fever or cough that improves and then returns or worsens.

Related guides

Sources

This article is for general information and is not a substitute for advice from your child’s doctor.

pediatricking
Author: pediatricking

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