Bad breath is often a symptom of dry mouth -- a condition known as “xerostomia.” Other symptoms of this problem include saliva that seems thick, sores or split skin at the corners of your mouth, and difficulty speaking and swallowing,.
Most xerostomia is related to medication. More than 400 drugs can affect the salivary glands. These include drugs for urinary incontinence, allergies, high blood pressure, depression, diarrhea and Parkinson's disease. Also, some over-the-counter medications often cause dry mouth.
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