30.09.2025
Bad breath almost always comes from the mouth
The notion that bad breath comes from the stomach is persistent. In about nine out of ten cases it arises in the mouth itself — usually on the back of the tongue, where bacteria hold on in the niches of the surface.
They break down protein residues, and in doing so sulphurous compounds are formed. Those are exactly what one smells. Gum inflammation, leaking fillings and a dry mouth intensify the effect.
Treatment therefore starts there: thorough cleaning, daily tongue cleaning, treatment of the inflammation. Mouthwash masks the smell but does not remove it.