Bad breath is awkward to talk about and hard to notice in yourself. It is commonly assumed that the cause lies in the stomach or digestion. In fact, in about 85% of cases the cause is in the mouth — and most of those are straightforward to fix.
The smell comes from sulphur compounds produced by anaerobic bacteria breaking down protein residues. These bacteria live where oxygen and a toothbrush do not reach.
Where those places are
- Tongue coating. The most common single cause. The back third of the tongue is covered in papillae, between which a bacterial coating builds up. Most people never clean their tongue.
- Between the teeth. If these spaces are not cleaned, food residue ferments there for hours.
- Gum pockets. With periodontitis, pockets form where bacteria live in an oxygen-free environment — the classic cause of persistent bad breath.
- Calculus. Its porous surface holds bacteria and it cannot be removed at home.
- Untreated decay. Decaying food sits in a deep cavity.
- A poorly cleaned denture. Especially one left in overnight.
Dry mouth
Saliva is the mouth’s natural cleaning system. When there is little of it, bacterial numbers rise quickly. That is why breath is worse in the morning — saliva flow drops at night. Persistent dry mouth is caused by many medicines (blood pressure, allergy, antidepressants), mouth breathing and drinking too little.
Why gum and mouthwash do not help
They mask the smell for 20–30 minutes but do not remove its source. Alcohol-based mouthwash often makes matters worse: it dries the mucosa, which in turn encourages bacterial growth. If you use mouthwash, choose an alcohol-free one.
What actually helps
- Cleaning the tongue. A tongue scraper or the back of the brush, from back to front, once a day. For many people this makes the biggest difference.
- Cleaning between the teeth daily. Floss or an interdental brush.
- Professional cleaning. Scale and stain removal by a hygienist — €100.
- Water. Enough fluid keeps saliva flowing.
- Treating decay and gum inflammation.
When the cause is not in the mouth
If the mouth is healthy and hygiene is good but the smell persists, it is worth investigating the tonsils (tonsil stones), sinuses, reflux or diabetes. A characteristic sweet, acetone-like smell can indicate undiagnosed diabetes and needs a family doctor.
How to check yourself
Breathing into your palm does not work — you acclimatise to your own smell. More reliable: run the back of a clean spoon over the back of your tongue, let it dry and smell it. Or simply ask someone you trust.
If bad breath persists, book an appointment at Unidenta in Tallinn — in most cases we find the cause in a single visit.