Bacteria

Food particles left in your mouth after a meal combine with bacteria to create a bad odor. Bacteria often collect on the back of your tongue.

Dry Mouth

Saliva cleanses your mouth, washing away many odor-causing bacteria. A dry mouth means too little saliva. This can lead to bad breath. Your mouth may become dry when you sleep, if you don't drink enough fluids, or because of certain medications.

Gum disease

Gum disease is an infection of the gums. The infection can also cause bad breath.

Tobacco

Smoking or chewing tobacco can make your breath smell. This bad breath stays with you even when you're not smoking or chewing.  

Certain Foods

Some types of food and drink can cause bad breath. These include garlic, onions, fish, cabbage, coffee, and alcohol.

Other Causes

There are other causes of bad breath. Braces, dentures, and other gear may smell if not kept clean. Certain medical problems may cause bad breath. Sinus problem that cause drainage into the throat may sometimes lead to mouth odor. And, in general, bad breath becomes more of a problem as you age.

Your Dentist Can Help

Your dentist can look for a cause of bad breath that can be treated. If a cause is found, treatment may improve your breath.

Finding the Cause

Some people think they have bad breath when they don't. First, your dentist confirms that you do have bad breath. Then, he or she looks for the cause. You're checked for gum disease and asked questions about food you eat, any medications you take, and how you care for your teeth.

Possible Treatments

If a problem such as gum disease is found, your dentist can help treat it. You may also be referred to another dental or medical specialist for evaluation and treatment. Sometimes, no cause is found that can be treated. In this case, your dentist can suggest things that may help fight bad breath.

What You Can Do

You can do some simple things to help avoid bad breath. First, brush after each meal and floss every day. Then, try some of these other tips.

Brush Your Tongue : Brush Your Tongue (or use a special tongue scraper) to clean off food and odor-causing bacteria. Brush as far back as you can.
Keep a Moist Mouth : Drink plenty of water and rinse your maouth with water every so often to keep saliva flowing. Chewing sugarless gum can also help.
Make Diet Changes : Try to avoid foods that can cause bad-smelling breath.
Stop Smoking : If you smoke or chew tobacco, quit. You'll be amazed how much better your breath will smell.
Ask About Mouth Rinses : Most over-the-counter mouthwashes only cover up bad breath for a short time. However, your dentist may suggest a prescription mouth rinse that can help kill odor-causing bacteria.

Fresh and Healthy Breath

If there is no underlying medical cause, you can usually achieve fresh smelling breath. Practice good oral hygiene. See your dentist regularly. And use what you've learned to keep your breath smelling great.