Flu in Children: What to Expect and When to Seek Care

How flu typically looks in children

Influenza tends to arrive fast. A child can seem fine in the morning and be noticeably unwell by afternoon. Common features include 1Ref 1Centers for Disease Control and Prevention (2025).Flu and Children.Flu symptoms in children, high-risk groups, potential complications, and annual vaccination recommendation for all children 6 months and older:

• Fever — often 102–104°F (38.9–40°C), sometimes higher, usually with sudden onset
• Chills and body aches — often described by older children as "everything hurts"
• Headache
• Fatigue — sometimes pronounced; a child who normally won't sit still may not want to get off the couch
• Dry cough
• Sore throat and runny nose — more variable
• Vomiting and diarrhea — more common in children than adults with flu

This rapid, all-at-once onset is often what distinguishes flu from a cold, which tends to build gradually.

Flu vs. cold — how to tell the difference

The distinction matters because flu carries a higher risk of complications in young children.

That said, the only way to know for certain is a rapid flu test, which a pediatric provider can perform in-office.

Who is at higher risk for flu complications?

While most healthy children recover from flu without serious complications, certain children are at substantially higher risk 1Ref 1Centers for Disease Control and Prevention (2025).Flu and Children.Flu symptoms in children, high-risk groups, potential complications, and annual vaccination recommendation for all children 6 months and older2Ref 2American Academy of Pediatrics (2025).The Flu: What Parents Need to Know.AAP guidance on flu symptoms in children, high-risk groups, supportive care, aspirin contraindication, and vaccination:

• Children under 5 years old, especially under 2
• Children with asthma, diabetes, heart conditions, or weakened immune systems
• Children who are obese
• Children receiving long-term aspirin therapy for certain conditions

Complications can include pneumonia, ear infections, sinus infections, worsening of underlying conditions, and, in serious cases, death. Flu hospitalizations are most common in children under 2 years old.

Treatment: what helps and what doesn't

Antiviral medicines can shorten the duration of flu and reduce complication risk — but they are most effective when started within 48 hours of symptoms beginning 3Ref 3Centers for Disease Control and Prevention (2025).Treatment of Flu in Children.FDA-approved antiviral medications for children, timing window for treatment, and which children benefit most from antivirals. The CDC approves four antivirals for children; oseltamivir (oral suspension) is the most commonly used, approved for children 14 days and older. It is typically recommended for 3Ref 3Centers for Disease Control and Prevention (2025).Treatment of Flu in Children.FDA-approved antiviral medications for children, timing window for treatment, and which children benefit most from antivirals:

• Children at high risk for complications
• Children who are hospitalized
• Sometimes for otherwise healthy children when started early

A pediatric provider determines whether antiviral treatment is appropriate.

Supportive care at home includes: - Fever reducers (acetaminophen or ibuprofen — check weight-based dosing; ibuprofen is for children 6 months and older) - Frequent fluids to prevent dehydration - Rest - Honey for cough in children over 1 year old (never in infants under 12 months)

Antibiotics do not treat flu. The flu is caused by a virus; antibiotics are only needed if a secondary bacterial infection develops.

Flu vaccination in children

Annual flu vaccination is recommended for all children 6 months and older by both the CDC and the American Academy of Pediatrics 1Ref 1Centers for Disease Control and Prevention (2025).Flu and Children.Flu symptoms in children, high-risk groups, potential complications, and annual vaccination recommendation for all children 6 months and older. It is available as a shot and, for eligible children, as a nasal spray.

For children receiving flu vaccine for the first time (generally under 9 years old), two doses spaced about 4 weeks apart may be needed — a provider can advise based on vaccination history. Vaccination typically takes about 2 weeks to provide full protection, so earlier in the season is better.