Bad breath: common causes and what actually helps
Common causes in the mouth
- Tongue coating: bacteria on the back of the tongue produce sulphur compounds. This is the most common source.
- Gum disease: bacteria in gum pockets. See bleeding gums.
- Food trapped between teeth, under a bridge or around a partly erupted wisdom tooth.
- Decay or a broken filling that traps food.
- Dry mouth, from medicines, mouth breathing, dehydration or fasting. See dry mouth.
- Dentures worn overnight or not cleaned daily.
Causes outside the mouth
- Tonsil stones, sinus infections and post-nasal drip
- Food and drink: garlic, onions, spices, coffee and alcohol (temporary)
- Smoking
- Less commonly, acid reflux or a medical condition such as poorly controlled diabetes, kidney or liver disease
The stomach is a less common source than many people think. If the dentist finds the mouth healthy and the smell persists, see a doctor.
What helps
- Clean your tongue once a day with a tongue scraper or your toothbrush, from back to front.
- Clean between your teeth daily with floss or interdental brushes.
- Brush twice a day with fluoride toothpaste.
- Drink water through the day.
- Take dentures out at night and clean them daily. See caring for dentures.
- Have a scaling and treat any gum disease or decay.
What about mouthwash?
Most mouthwashes mask odour for a short time without removing the cause. Alcohol-containing mouthwashes can dry the mouth and make things worse for some people. A mouthwash is an add-on, not a substitute for cleaning. See toothbrushes and mouthwash.
Frequently asked questions
Why do I still have bad breath after brushing?
Brushing the teeth alone leaves the tongue coating and the spaces between teeth, the two most common sources. Gum disease and a dry mouth also cause odour that brushing does not remove.
Can bad breath come from the stomach?
Occasionally, for example with reflux, but this is much less common than causes in the mouth, nose and throat. Have your mouth checked first.
When should I see a doctor about bad breath?
If your dentist finds no cause in the mouth, or you also have a blocked nose, sinus pain, sore throat, reflux symptoms or other health concerns.
Questions about your teeth?
Book a check-up. You will hear what we find, the options and the fee before anything is done.