BAD BREATH

Causes

There are many causes of bad breath. 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 such 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 blood alcohol levels by breath tests. Alcohol itself has almost no odor, however. The characteristic smell on the 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 odorous bacteria. A colorless, sticky film of bacteria — plaque — forms on your teeth. If not brushed away, plaque can irritate your gums (a condition called gingivitis) and cause tooth decay. Eventually, plaque-filled pockets can form between your teeth and gums (periodontitis), worsening the problem — and your breath. Dentures that aren't cleaned or don't fit properly can also 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 is natural during sleep. It's the cause of "morning breath." But dry mouth is especially a problem if you sleep with your mouth open. Some medications and smoking can also lead to chronic dry mouth, as can a problem with your salivary glands.

• Disease. 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 into your food pipe (a condition called gastroesophageal reflux disease, GERD) andhiatal hernia (a slight protrusion of the stomach into the chest cavity) 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 (mouth) 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 suffer from periodontal disease, an additional source of bad breath.

• Severe dieting. Dieters may develop unpleasant "fruity" breath from ketoacidosis, the breakdown of body chemicals during fasting.