Causes of bad breath

The causes of bad breath are numerous. They include:

• Food.The breakdown of food particles in and around your teeth can cause a foul odor. Eating foods containing volatile oils is another source of bad breath. Onions and garlic are the best known examples, but other vegetables and spices also can cause bad breath. After these foods are digested and the pungent oils are absorbed into your bloodstream, they're carried to your lungs and are given off in your breath until the food is eliminated from your body. Alcohol behaves in the same fashion, allowing the measurement of alcohol levels by breath tests. Alcohol itself has almost no odor, however. The characteristic smell on your breath is mainly the odor of other components of the beverage.
• Dental problems.Poor dental hygiene and periodontal disease can be a source of bad breath. If you don't brush and floss daily, food particles remain in your mouth, collecting bacteria and emitting hydrogen sulfur vapors. A colorless, sticky film of bacteria (plaque) forms on your teeth. If not brushed away, plaque can irritate your gums (gingivitis) and cause tooth decay. Eventually, plaque-filled pockets can form between your teeth and gums (periodontitis), worsening this problem — and your breath. Dentures that aren't cleaned regularly or don't fit properly also can harbor odor-causing bacteria and food particles.
• Dry mouth.Saliva helps cleanse and moisten your mouth. A dry mouth enables dead cells to accumulate on your tongue, gums and cheeks. These cells then decompose and cause odor. Dry mouth naturally occurs during sleep. It's what causes "morning breath." Dry mouth is even more of a problem if you sleep with your mouth open. Some medications as well as smoking can lead to a chronic dry mouth, as can a problem with your salivary glands.
• Diseases.Chronic lung infections and lung abscesses can produce very foul-smelling breath. Several other illnesses can cause a distinctive breath odor. Kidney failure can cause a urine-like odor, and liver failure may cause an odor described as "fishy." People with uncontrolled diabetes often have a fruity breath odor. Chronic reflux of stomach acids from your stomach (gastroesophageal reflux disease, or GERD) and a slight protrusion of the stomach into the chest cavity (hiatal hernia) also can produce bad breath.
• Mouth, nose and throat conditions.Bad breath is also associated with sinus infections because nasal discharge from your sinuses into the back of your throat can cause mouth odor. A child with bad breath may have a foreign object lodged in his or her nose. A bean or small item stuck in the nose can cause persistent nasal discharge and a foul odor. Strep throat, tonsillitis and mononucleosis can cause bad breath until the throat infection clears. Bronchitis and other upper respiratory infections in which you cough up odorous sputum are other sources of bad breath. Canker sores may be related to bad breath, especially if they accompany periodontal disease.
• Tobacco products.Smoking dries out your mouth and causes its own unpleasant mouth odor. Tobacco users are also more likely to have periodontal disease, an additional source of bad breath.
• Severe dieting.Dieters may develop unpleasant "fruity" breath from ketoacidosis, the breakdown of chemicals during fasting.

Bad breath can usually be eliminated with good dental hygiene.

When to seek medical advice

Most people can prevent or improve bad breath by practicing proper dental hygiene. If bad breath persists despite self-care, see your dentist. If the cause isn't dental, see your doctor to determine a possible medical cause. You may need a physical examination and testing to pinpoint the underlying cause.

Self-care

Try the following steps to improve or prevent bad breath:

• Brush your teeth after you eat.Keep a toothbrush at work to brush after eating.
• Floss at least once a day.Proper flossing removes food particles and plaque from between your teeth.
• Brush your tongue.Giving your tongue a good brushing removes dead cells, bacteria and food debris. Use a soft-bristled toothbrush and brush your tongue with at least five to 15 strokes. Pay particular attention to the middle third of the tongue, where most of the bacteria tend to collect.
• Clean your dentures well.If you wear a bridge or a partial or complete denture, clean it thoroughly at least once a day or as directed by your dentist.
• Drink plenty of water.To keep your mouth moist, be sure to consume plenty of water — not coffee, soft drinks or alcohol. Chewing gum (preferably sugarless) or sucking on candy (preferably sugarless) also stimulates saliva, washing away food particles and bacteria. If you have chronic dry mouth, your dentist or doctor may additionally prescribe an artificial saliva preparation or an oral medication that stimulates the flow of saliva.
• Use a fairly new toothbrush.Change your toothbrush every three to four months, and choose a soft-bristled toothbrush.
• Schedule regular dental checkups.At least twice a year, see your dentist to have your teeth or dentures examined and cleaned.

You can teach your school-age children to brush and floss their teeth regularly and to brush their tongues to prevent bad breath. However, don't give children mouthwash to use, because many mouthwash products contain alcohol and can pose a risk for children if swallowed.