IllnesschevronFlu (Influenza)

Flu (Influenza)

By Dr. Corey A. Fish (He/Him)
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What is the Flu?

Influenza (commonly called the Flu) is a respiratory infection of the nose, throat, and the main airways to the lungs. It typically begins with a high Fever, body aches, runny or stuffy nose, headache, fatigue, and/or sore throat. If your child doesn't have a fever with early symptoms, it is unlikely to be the flu. Flu outbreaks typically occur during the winter and early spring months but can vary based on the year and in different areas of the country.

Early Flu symptoms:

High fever (temp of 100.4 or higher)


Runny nose

Nasal congestion


Fussiness or irritability


Sore Throat

Severe Flu symptoms:

The flu can cause significant coughing and congestion. In some cases, this can lead to pneumonia. With children that do end up with pneumonia, additional support for your kiddo may be needed.

The following are signs of severe Flu:

  • A fever beyond 5 days
  • Labored breathing or retractions: This is when the skin between the ribs, and/or above and below the ribcage gets sucked in when kiddos are breathing.
  • Low level of responsiveness


  • Congestion
  • Cough
  • Dehydration
  • Difficulty breathing 
  • Frequent waking during the night 
  • Infants who are feeding will likely have difficulty, and often appear sleepy and/or irritable.
  • Pain/Discomfort
  • Wheezing

It's important to seek medical attention once severe symptoms appear or you notice significant changes in your child's wellness so that a proper evaluation can be conducted. Most cases are not severe.

How severe is the Flu?

The flu is a virus that is very common in certain months throughout the year. It can vary in severity depending on the conditions your kiddo may have prior to the infection of the virus itself. Viral illnesses typically resolve on their own, and do not require medications such as antibiotics to resolve. Most children recover well with rest and medications to treat symptoms. In some cases, the flu can be treated with antivirals to shorten the duration of the illness and decrease risks of complications.  

In infants and children <2 years

Children younger than 2 years old can be impacted by complications such as pneumonia and dehydration more than other age groups. The flu can also make preexisting chronic health conditions worse, such as asthma. Infants under 2 months of age with a fever of 100.4 or more should be evaluated in the emergency room. Young babies and premature babies should be monitored closely for signs of respiratory distress.

In older, healthy, children and adults

The flu is a virus that takes rest, fluids, and time to get over in order to make a full recovery. Most older, generally healthy children and adults recover easily from influenza without complications, and keeping them comfortable during their symptoms is the mainstay of treatment. For those that have underlying health conditions that may put them at risk for complications from the flu, they should see their primary care provider as soon as possible if they suspect they have influenza, since antiviral medications may be indicated.

What causes the Flu?

The flu is caused by infection from viral particles via contact or inhalation. Close contact with someone who is infected is the most likely source of transmission. It may also be picked up from contaminated surfaces. 

Is the Flu contagious?

Highly contagious
Spreads by exposure

The severity varies from year to year. The flu is spread by coughing, sneezing, and touching contaminated surfaces that have the virus on them. The virus can live on surfaces for a short amount of time, so if someone who coughed into their hands touches a doorknob or children's toy without washing their hands first, these surfaces become contaminated.

How to protect your child from the Flu

What should I do if I think my child has the Flu?

The first step is supportive care at home and continued monitoring for worsening symptoms. Make an appointment to get a flu test done to confirm the cause of the symptoms, especially if your child has underlying health conditions that may put them at higher risk of complications or severe disease.

What is the treatment for Flu?

Supportive care at home & antiviral medications or treating symptoms with over-the-counter medications.

Flu Treatments

Nasal Congestion:
Try nasal saline & suctioning. Apply nasal saline spray or drops to nasal passages, let sit for 3-5 minutes. Then using a bulb suction or a Nose Frida, gently suction out mucus from both nostrils. Perform this 3-4 times a day for best results, especially before bedtime and nap, and before eating. (Do not over-suction, as this could lead to increased inflammation in the nasal passages.)

Use of a cool-mist humidifier at bedtime, naptime, or throughout the day.

You can help manage fevers and discomfort with over-the-counter (OTC) fever reducers like acetaminophen (Tylenol), or ibuprofen (Advil or Motrin).  It is best to dose this according to your child's weight. You can find Brave Care's dosing calculator here for the most accurate dose. 

Note - never give aspirin to children, and ibuprofen is only to be used in children 6 months of age and older.

Severe, hacking cough:
For children over one year, honey is as or more effective than most cough medicines. Several brands have honey as an active ingredient. Zarbees is good. Kids younger than 12 months old should not have honey, but Zarbees makes a honey-free cough medicine that works well for infants. 

Do not give cough medicine that contain dextromethorphan to children under the age of 4 due to serious side effects. Use caution even in children 4-11 and always follow package directions carefully.

Push fluids to maintain your child’s hydration. If they are not eating much at all, it’s important to give them an electrolyte solution such as Pedialyte to maintain proper electrolyte balance. 

Keep track of the number of wet diapers and the number of voids. If there is a significant decrease in urine output, you should have your child seen.

Tamiflu (oseltamivir):
Tamiflu is a medication that must be administered within the first 48 hours of a fever from the flu in order to be effective. It marginally shortens the duration of the illness but may help prevent complications in kids who have underlying medical conditions such as asthma or other diseases of the heart, lungs, or immune system. Additionally Tamiflu can be given to family members without symptoms in order to prevent transmission of the flu.

To ease breathing during heavy congestion the child may prefer to sit or lay at an elevated position instead of lying down flat (infants under 1yr of age should always be flat on their back for sleep). Frequent waking is common, infants who are feeding will likely have difficulty and/or be irritable.

Not sure if these symptoms fit your kiddo’s symptoms?Our Panic-Free Symptom Checker can walk you through tons of common kiddo symptoms, and let you know if it’s time to see a doctor. Try Symptom Checker

When should I seek medical care for my child from an Urgent Care or Emergency Room?

Go to an Emergency Room in the following situations:

  • If your child is under two months old and has a fever of 100.4 or more.
  • You have difficulty waking your child up or they are not alert when awake. 
  • Your child is very weak.
  • They have a bluish or grey color to their lips or face.

Go to Urgent Care in the following situations:

  • If your child is between 2 and 3 months with a fever of 100.4.
  • If your child is between 2 and 3 months and you suspect dehydration. Signs of dehydration would be less than 6-11 diapers in 24hrs.
  • If your child is older and out of diapers. Signs of dehydration would be no urine for over 8hrs.
  • Fever longer than 5 days in children over 3 months.
  • A cough that persists for longer than 2 weeks.
  • Your child has difficulty breathing.

What is the typical duration of the Flu

Most flu infections resolve at-home with supportive care in about 1 week. A runny nose is common for 7-14 days. If fever occurs, it generally lasts 2-3 days but can last up to 4-5. The worst of the symptoms typically peak around day 3-4, then start to gradually improve.

Many children may continue to cough even after recovering. This is commonly referred to as a “post-viral cough,” and could linger for up to 2 weeks, or occasionally longer in some children. After they have fully recovered, the cough should not be treated as a sign of ongoing infection, but for any children with an ongoing cough, it may be helpful to have them evaluated as a precaution.

Anything else?

The CDC does not recommend anti-viral medications for low-risk children with normal influenza. Your child does not need to see their doctor unless they have possible complications from the flu, the reasons for a visit listed above, or if you have concerns.

DisclaimerThis illness guide is not a substitute for professional medical advice, diagnosis or treatment.
911If you think your child may have a life threatening emergency, immediately call your doctor or dial 911.
Headshot of Dr. Corey A. Fish, MD, Founder and Chief Medical Officer, He/Him
Dr. Corey A. Fish (He/Him)

Dr. Corey Fish attended the University of Washington School of Medicine before traveling to Austin, Texas for his pediatric residency at Dell Children’s Medical Center of Central Texas. Now a practicing pediatrician with over 10 years of experience Dr. Fish is passionate about delivering high-quality urgent and after-hours care for children. When he’s not working, you’ll find him cycling with his wife, backcountry skiing, and playing guitar.

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