You lean over to whisper something to your friend and you can tell by the look on your friend's face that something is up. Could it be your breath? Maybe you shouldn't have put extra onions on your hamburger at lunch. What's a kid with smelly breath to do?

The good news is that bad breath happens to everyone once in a while. Let's find out how to detect it, prevent it, and even treat it.

What's That Smell?

Bad breath is the common name for the medical condition known as halitosis (say: hal-uh-TOE-sis). Many different things can cause halitosis — from not brushing your teeth to certain medical conditions.

Sometimes, a person's bad breath can blow you away — and he or she may not realize there's a problem. There are tactful (nice) ways of letting someone know about bad breath. You could offer mints or sugarless gum without having to say anything.

If you need to tell a friend he or she has bad breath, you could say that you understand foods can cause bad breath because you've had it before yourself. By letting someone know that bad breath isn't something unusual, you'll make your friend feel more comfortable and less embarrassed about accepting your piece of chewing gum.

If you suspect your own breath is foul, ask someone who will give you an honest answer without making fun of you. (Just don't ask your brother or sister — they just might tell you your breath stinks even when it doesn't!)

Although everyone gets bad breath sometimes, if you have bad breath a lot, you may need to visit your dentist or doctor.

What Causes Bad Breath?

Here are three common causes of bad breath:

1. foods and drinks, such as garlic, onions, cheese, orange juice, and soda
2. poor dental hygiene (say: HI-jeen), meaning not brushing and flossing regularly
3. smoking and other tobacco use

Poor oral hygiene leads to bad breath because when food particles are left in your mouth, they can rot and start to smell. The food bits may begin to collect bacteria, which can be smelly, too.

Not brushing your teeth regularly will let plaque (a sticky, colorless film) build up on your teeth. Plaque is a great place for bacteria to live and yet another reason why breath can turn foul.

Preventing Smelly Breath

So what's a kid to do? Don't smoke or use tobacco products, of course. And take care of your mouth by brushing your teeth at least twice a day and flossing once a day. Brush your tongue, too, because bacteria can grow there. Flossing once a day helps get rid of particles wedged between your teeth. Also, visit your dentist twice a year for regular checkups and cleanings.

Not only will you get a thorough cleaning, the dentist will look around your mouth for any potential problems, including those that can affect breath. For example, gum disease, also known as periodontal (say: per-ee-uh-DON-tul) disease, can cause bad breath and damage your teeth.

If you're concerned about bad breath, tell your doctor or dentist. But don't be surprised if he or she leans in and take a big whiff! Smell is one way doctors and dentists can help figure out what's causing the problem. The way a person's breath smells can be a clue to what's wrong. For instance, if someone has uncontrolled diabetes, his or her breath might smell like acetone (the same stuff that's in nail polish remover).

If you have bad breath all the time and the reason can't be determined by your dentist, he or she may refer you to a doctor to make sure no other medical condition could be causing it. Sometimes sinus problems, and rarely liver or kidney problems, can cause bad breath.

Usually, there's a less complicated reason for bad breath — like what you had for lunch. So keep up with your brushing and flossing and you should be breathing easy — and odor free!