Basically, all the food eaten begins to be broken down in your mouth. As foods are digested and absorbed into the bloodstream, they are eventually carried to your lungs and given off in your breath. If you eat foods with strong odors (such as garlic or onions), brushing and flossing — even mouthwash — merely covers up the odor temporarily. The odor will not go away completely until the foods have passed through your body.

 

If you don’t brush and floss teeth daily, food particles can remain in your mouth, promoting bacterial growth between teeth, around the gums, and on the tongue. This causes bad breath. Antibacterial mouth rinses also can help reduce bacteria.

 

Persistent bad breath or a bad taste in the mouth may be a warning sign of gum (periodontal) disease. Gum disease is caused by the buildup of plaque on teeth. Bacteria cause the formation of toxins to form, which irritate the gums. If gum disease continues untreated, it can damage the gums and jawbone.

 

Other dental causes of bad breath include poorly fitting dental appliances, yeast infections of the mouth, and dental caries (cavities).

 

The medical condition dry mouth (also called xerostomia) also can cause bad breath. Saliva is necessary to moisten the mouth, neutralize acids produced by plaque, and wash away dead cells that accumulate on the tongue, gums, and cheeks. If not removed, these cells decompose and can cause bad breath. Dry mouth may be a side effect of various medications, salivary gland problems, or continuous breathing through the mouth.