SSM Cardinal Glennon Children's Medical Center
(314) 577-5600


What's the Flu?

Influenza (say: in-floo-EN-zah) is also called the flu. It's an infection that causes a fever, chills, cough, body aches, headaches, and sometimes earaches or sinus problems.

The flu is caused by the influenza virus (say: VY-rus). A virus is a microorganism (say: my-kroh-OR-guh-niz-uhm), which means it's so small that you would need a strong microscope to see it.

What's the Flu Vaccine?

Health experts recommend that all people age 6 months and older get the flu vaccine (say: vak-SEEN) each year. If you're a kid, that means you!

The flu vaccine is available as a shot (injected through the skin) or as a spray mist (into the nostrils). Most kids older than 2 can get the spray mist.

If you get the flu vaccine, by nose spray or shot, it will protect you from getting a bad case of the flu. You either won't get the flu at all, or if you do get it, you will have only mild symptoms and you should get better pretty quickly.

Here's what the vaccine means for most kids:

  • Kids older than 9 need only one dose.
  • Are you younger than 9? You will need two doses if this is your first time getting the vaccine, or if you've only had one dose in the past.
    • If you need two doses, you'll get one dose and then come back at least a month later to get the second one.
  • If you've gotten the flu vaccine at least twice in the past, you will only need to get one dose. (Your parents and doctor can look this up.)

Certain people are at higher risk of problems from the flu, including:

  • pregnant women
  • kids younger than age 5
  • people age 65 and older
  • people of any age who have long-term health conditions

So if you're a kid who has asthma, diabetes, or another health problem, it's especially important that you get the flu vaccine.

Flu vaccines are usually given in the fall, before flu season starts. Flu season — the months of the year when a lot of people have the flu and it's easy to catch it — usually starts in October and ends in May.

Why Get a Vaccine Every Year?

You might wonder why you have to get a flu vaccine every year. Here's why: There are lots of different flu viruses. Each year, researchers choose the three or four viruses most likely to cause trouble. The flu vaccine includes protection against those three or four, which can vary from year to year.

How Does the Flu Spread?

This virus gets around in little drops that spray out of an infected person's mouth and nose when he or she sneezes, coughs, or even laughs. You can catch the flu from someone who has it if you breathe in some of those tiny flu-infected drops.

You also can catch the flu if those drops get on your hands and you touch your mouth or nose. No wonder people are always saying to cough or sneeze into your elbow, not your hands. And while you're at it, wash your hands well and often!

What If You Get the Flu?

If your doctor thinks you might have the flu, sometimes he or she will use a long cotton swab to get a sample of the gunk in your nose. Testing this sample in a lab can determine if you have the flu.

But usually this isn't necessary. Based on your symptoms and how you look during the visit, your doctor can usually tell if you have the flu, especially during times when a lot of flu is going around your town.

If your doctor says you have the flu, start taking these steps to feel better:

  • Rest in bed or on the couch.
  • Drink lots of liquids, like water, chicken broth, and other fluids.
  • Take the medicine your mom or dad gives you to ease your fever, aches, and pains.
  • Tell your mom or dad if you have trouble breathing, if you are feeling worse instead of better, or if you aren't peeing as much as usual. These are signs that you may need to see the doctor again.

Most of the time, kids with the flu feel better in about a week. Until they do, they have to stay home from school and take it easy.

We hope you're flu-free this year, but if you do get the flu, now you know what to do!

Reviewed by: Elana Pearl Ben-Joseph, MD
Date reviewed: September 2015