More than 80 million people suffer from chronic halitosis, or bad breath. In most cases it originates from the gums and tongue. The odor is caused by wastes from bacteria in the mouth, the decay of food particles, other debris in your mouth and poor oral hygiene. The decay and debris produce a sulfur compound that causes the unpleasant odor.

What causes bad breath?

Bad breath is primarily caused by poor oral hygiene but can also be caused by retained food particles or gum disease.

Does bad breath come from other sources than the mouth?

Bad breath also may occur in people who have a medical infection, diabetes, kidney failure or a liver malfunction. Xerostomia (dry mouth) and tobacco also contribute to this problem. Cancer patients who undergo radiation therapy may experience dry mouth. Even stress, dieting, snoring, age and hormonal changes can have an effect on your breath. An odor that comes from the back of your tongue may indicate postnasal drip. This is where mucus secretion, which comes from the nose and moves down your throat, gets stuck on the tongue and causes an odor.

Why is saliva so important in the fight against bad breath?

Saliva is the key ingredient in your mouth that helps keep the odor under control because it helps wash away food particles and bacteria, the primary cause of bad breath. When you sleep, however, salivary glands slow down the production of saliva, allowing the bacteria to grow inside the mouth. To alleviate "morning mouth," brush your teeth and eat a morning meal. Morning mouth also is associated with hunger or fasting. Those who skip breakfast, beware, because the odor may reappear even if you've brushed your teeth.

Do certain foods cause bad breath?

Very spicy foods, such as onions and garlic, and coffee may be detected on a person's breath for up to 72 hours after digestion. Onions, for example, are absorbed by the stomach, and the odor is then excreted through the lungs. Studies even have shown that garlic rubbed on the soles of the feet can show up on the breath.

How do I control bad breath?

It is important to practice good oral hygiene, such as brushing and flossing your teeth at least twice a day. Proper brushing, including brushing the tongue, cheeks and the roof of the mouth, will remove bacteria and food particles. Flossing removes accumulated bacteria, plaque and food that may be trapped between teeth. To alleviate odors, clean your tongue with your toothbrush or a tongue scraper, a plastic tool that scrapes away bacteria that builds on the tongue. Chewing sugar-free gum also may help control odor. If you have dentures or a removable appliance, such as a retainer or mouthguard, clean the appliance thoroughly before placing it back in your mouth. Before you use mouthrinses, deodorizing sprays or tablets, talk with your dentist, because these products only mask the odor temporarily and some products work better than others.

What is my dentist's role?

Visit your dentist regularly, because checkups will help detect any physical problems. Checkups also help get rid of the plaque and bacteria that build up on your teeth. If you think that you suffer from bad breath, your dentist can help determine its source. He or she may ask you to schedule a separate appointment to find the source of the odor. Or, if your dentist believes that the problem is caused from a systemic (internal) source, such as an infection, he or she may refer you to your family physician or a specialist to help remedy the cause of the problem.