Patient-friendly definition from the DentistsDirectory.org dental glossary.
Halitosis is the medical term for persistent bad breath. It affects an estimated 25–30% of the population and causes significant social and psychological distress. Despite a multibillion-dollar mouthwash industry built around the symptom, genuine resolution requires identifying and treating the underlying cause — mouthwash provides temporary masking at best.
Approximately 85–90% of chronic bad breath originates in the mouth. The culprits are volatile sulfur compounds (VSCs) — odorous gases produced when anaerobic bacteria in the mouth break down proteins from dead cells, food debris, and saliva. These bacteria colonise three main habitats: the dorsum (back surface) of the tongue, which is responsible for 50–80% of oral halitosis; the periodontal pockets of gum disease; and the spaces between poorly flossed teeth. Dry mouth dramatically worsens halitosis by reducing saliva flow, which normally washes away food particles and bacteria. The remaining 10–15% of halitosis originates beyond the mouth — in the sinuses, throat, lungs, or digestive system — and requires medical rather than dental investigation.
Tongue scraping is the single highest-impact addition most patients can make — studies show a dedicated tongue scraper reduces VSC production by approximately 75%. Consistent flossing removes the bacterial substrate between teeth. Treating active gum disease eliminates its contribution. Staying hydrated and using sugar-free gum or candy stimulates saliva. If bad breath persists despite excellent oral hygiene and a clean dental examination, a medical consultation is warranted to rule out sinus, respiratory, or gastrointestinal causes.