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What Causes Bad Breath?

Medically reviewed by: Steven Dowshen, MD

Bad breath, or halitosis, can be a major problem, especially when you're about to snuggle with your sweetie or whisper a joke to your friend. The good news is that bad breath can often be prevented with some simple steps.

Bad breath is caused by odor-producing bacteria that grow in the mouth. When you don't brush and floss regularly, bacteria accumulate on the bits of food left in your mouth and between your teeth. The sulfur compounds released by these bacteria make your breath smell.

Certain foods, especially ones like garlic and onions that contain pungent oils, can contribute to bad breath because the oils are carried to your lungs and out through your mouth. Smoking is also a major cause of bad breath.

There are lots of myths about taking care of bad breath. Here are three things you may have heard about bad breath that are not true:

Myth #1: Mouthwash will make bad breath go away.

Mouthwash only gets rid of bad breath temporarily. If you do use mouthwash, look for an antiseptic (kills the germs that cause bad breath) and plaque-reducing one with a seal from the American Dental Association (ADA). When you're deciding which dental products to toss into your shopping cart, it's always a good idea to look for those that are accepted by the ADA. Also, ask your dentist for recommendations.

Myth #2: As long as you brush your teeth, you shouldn't have bad breath.

The truth is that most people only brush their teeth for 30 to 45 seconds, which just doesn't cut it. To sufficiently clean all the surfaces of your teeth, you should brush for at least 2 minutes at least twice a day. Remember to brush your tongue, too — bacteria love to hang out there. It's equally important to floss because brushing alone won't remove harmful plaque and food particles that become stuck between your teeth and gums.

Myth #3: If you breathe into your hand, you'll know when you have bad breath.

Wrong! When you breathe, you don't use your throat the same way you do when you talk. When you talk, you tend to bring out the odors from the back of your mouth (where bad breath originates), which simply breathing doesn't do. Also, because we tend to get used to our own smells, it's hard for a person to tell if he or she has bad breath.

If you're concerned about bad breath, make sure you're taking care of your teeth and mouth properly. Some sugar-free gums and mints can temporarily mask odors, too.

If you brush and floss properly and visit your dentist for regular cleanings, but your bad breath persists, you may have a medical problem like sinusitis or gum disease. Call your doctor or dentist if you suspect a problem. They can figure out if something else is behind your bad breath and help you take care of it.

Medically reviewed by: Steven Dowshen, MD