Chronic Bad Breath: Finding the Real Cause

Persistent bad breath is a symptom, and the source is almost always identifiable. Roughly 85 percent of cases originate in the mouth.

June 18, 2026 · 4 min read · Dr. Nicki Tajalli, D.D.S.

The tongue is the usual suspect

The rough back surface of the tongue harbors bacteria producing volatile sulfur compounds. A tongue scraper used daily addresses more halitosis than any mouthwash on the shelf.

Gum pockets and old restorations

Deep periodontal pockets and leaking crowns or fillings shelter anaerobic bacteria that brushing cannot reach. Treating those sources resolves the odor at its origin.

Dry mouth

Saliva is the mouth's rinse cycle. Antihistamines, blood pressure medication, antidepressants, mouth breathing, and CPAP use all reduce flow. Water, xylitol lozenges, and alcohol-free rinses help.

When it is not the mouth

Sinus drainage, tonsil stones, reflux, and uncontrolled diabetes account for the remainder. If a dental exam finds nothing, that is useful information for your physician.

Key takeaways

  • Scrape your tongue daily.
  • Alcohol-based rinses dry the mouth and worsen odor.
  • Rule out the mouth first, then look elsewhere.

This article is general information, not a diagnosis. Your situation deserves an exam.