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.
In addition, odor-causing bacteria and food particles can cause bad breath if dentures are not properly cleaned.
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.
Many other diseases and illnesses may cause bad breath. Here are some to be aware of: respiratory tract infections such as pneumonia or bronchitis, chronic sinus infections, postnasal drip, diabetes, chronic acid reflux, and liver or kidney problems.