Influenza (The “Flu”)

Influenza, or flu, is a respiratory disease caused by viruses that can spread from person to person. Symptoms include fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills and fatigue.

What Is Influenza?

Influenza, also known as the flu, is an illness caused by a virus. Different types (strains) of the flu virus cause illnesses each year. These germs are contagious and easily spread from person to person.

How the Flu Spreads

  • The flu virus spreads when a person breathes in air from an infected person who coughs, sneezes, or laughs less than 3 feet from another person.
  • It can also get into your body if you touch your mouth, nose, or eyes after you touched something that an infected person sneezed, coughed, or drooled on. 

Flu germs can live for up to 2 days on hard surfaces like toys, tables, computer keyboards, phones, and doorknobs.

An infected person can infect others before they knows they have the flu and for at least 7 days after getting sick.

What Are Symptoms of the Flu?

Symptoms of the flu and a common cold look alike. However, flu symptoms come on faster and are generally worse. A child who has the flu may have some or all of these:

In some people, the flu may lead to sinus or ear infections, pneumonia or being dried out (dehydrated). People who have diabetes, heart, lung, or kidney problems or a weakened immune system may have a harder time fighting the flu. These people should contact their doctor or health care provider if they get sick.

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We've Got You Covered This Respiratory Season

Cold and flu season is here. Autumn means falling leaves and respiratory ailments. We’ve compiled resources about cold, flu, RSV and other seasonal conditions that make kids sick this time of year.

Visit Our Respiratory Illness Guide

Prevent the Flu With the Flu Vaccine

  • The best way to help prevent the flu or keep you and your child from getting a bad case of it, is to get a flu vaccine each year.
    • Anyone who is 6 months or older should have a flu vaccine each year.
    • If your child is younger than 8 years old and getting the vaccine for the first time, they should get 2 doses in early fall, as soon as it's available.
  • Scientists make a new vaccine formula each year based on which strains they predict will appear. That is why the vaccine works better some years than others.
  • There are 2 types of flu vaccines:
    • One uses a virus that is dead. You get this vaccine in a shot (by injection). This is the best choice for children over 6 months of age.
    • The other uses live, weakened virus. You get this vaccine through the nose (intranasal). The intranasal flu vaccine:
      • Should only be given to people who cannot take the shot.
      • Is for healthy people ages 2 to 49 years who are not pregnant.
      • Should not be given to anyone caring for a person with a weak immune system.
  • Before getting the vaccine, tell your doctor or health care provider if:
    • You or your child have any medical problems or allergies. The vaccine is safe for anyone with an egg allergy or an allergy to thimerosal. (Thimerosal is a preservative used in some vaccines. No pre-packaged, single dose flu vaccine contains thimerosal. Also, thimerosal is not in any vaccine given to children.)
  • You are pregnant. The flu vaccine is safe and recommended during pregnancy. 

Other Ways to Prevent the Flu

There are other things you and your child can do to keep from getting the flu.

  • Avoid touching your eyes, nose, and mouth whenever possible.
  • Cover your nose and mouth with a tissue when coughing or sneezing. Throw tissues away where no one else can touch them. Wash hands afterward.
  • Frequent and good hand washing is very important. Wash hands with soap and water for 15 to 20 seconds, or the same amount of time it takes to sing "Happy Birthday" 2 times.
  • If you do not have access to soap and water, clean hands with alcohol-based hand wipes or gel hand sanitizer that is at least 60% alcohol. Rub hands until dry.
  • Wash things used for drinking and eating in hot, soapy water. Do not share them.
  • Wipe down hard surfaces that may have virus germs on them. Use a disinfectant wipe or soap and water.
  • Stay away from people who are sick.
  • Stay home when you are sick.
  • Practice good health habits. Eat a balanced diet, drink plenty of water, and get enough rest to keep your immune system strong.

How to Treat the Flu

  • The doctor may order an antiviral medicine to help your child to get well sooner. It works best if started within 48 hours after symptoms begin.
  • Since a virus causes the flu, antibiotics will not help.
  • Check your child’s temperature using a digital thermometer. Never use a mercury thermometer. Wash the thermometer thoroughly after each use.
    • Use only a rectal (in baby’s bottom) thermometer in infants under 3 months of age.
    • For infants 4 months of age or older, take rectal, ear, or armpit (axillary) temperatures.
    • When your child reaches 4 years of age, mouth (oral) temperatures are okay.
  • If your child has pain or fever, you may give acetaminophen (Tylenol®) or ibuprofen (Advil®, Motrin®) as directed. Read the label to know the right dose for your child.
  • Do not give your child aspirin or products that contain aspirin.  Do not give ibuprofen to children younger than 6 months.

When to Call the Doctor

 Call your child's doctor or health care provider if they have:

  • A high fever
    • Is younger than 3 months of age and has a temperature of 100.4°Fahrenheit (F) or 38° Celsius (C) or higher.
    • Is older than 3 months of age and has a temperature:
      • Of 104°F (40° C) or above
      • Above 102°F (38.9° C)
      • That has been treated to bring it down, but it has not worked.
    • At any age, has a fever and:
      • Looks very ill, very fussy, or very drowsy.
      • Has a stiff neck, a bad headache, or very sore throat.
      • Has an unusual rash.
      • Has immune system problems that make them more likely to get sick, such as sickle cell disease, cancer, or takes medicine that weakens the immune system.
  • Little or no appetite, will not eat or drink, or shows signs of dehydration like:
    • Does not pee (urinate)
    • Urine is very dark
      • Newborn (0 to 4 months of age) has less than 6 wet diapers in a day
      • Child (4 months or older) has less than 3 wet diapers in a day or pees less than 3 times in a day.
    • Dry or sticky mouth
    • Hard or fast breathing
    • No tears when crying
    • Sunken-looking eyes
    • Soft spot on head is flat, sunken, or pulled in
    • Abdominal pain (bellyache) that will not go away
    • Hard to wake up (lethargic), acts confused, or does not know what they are doing
  • Any other symptoms that do not go away or get worse 

Visiting the Doctor’s Office, Clinic, or Hospital

  • If you have flu symptoms, you may be asked to wear a mask to protect others. 
  • Do not worry if you see staff and others wearing masks. They are preventing the spread of germs.

Helping Hands Patient Education Materials

Written and illustrated by medical, nursing and allied health professionals at Nationwide Children's Hospital, Helping Hand instructions are intended as a supplement to verbal instructions provided by a medical professional. The information is periodically reviewed and revised to reflect our current practice. However, Nationwide Children's Hospital is not responsible for any consequences resulting from the use or misuse of the information in the Helping Hands.

HH-I-245  | ©2004, revised 9/22, Nationwide Children’s Hospital