Where bad breath comes from
| Source | Signs | Treatment |
|---|---|---|
| Coated tongue | White or yellow coating at the back of the tongue | Daily tongue cleaning with a scraper or brush |
| Gum disease | Bleeding gums, swollen gums, receding gums | Scaling or deep cleaning by our periodontist |
| Tartar | Hard yellow or brown deposits along the gum line | Professional cleaning |
| Decay, leaking fillings, old crowns | Food packing, a bad taste from one area | Fillings or replacing the old restoration |
| Wisdom tooth infection | Swelling and a bad taste at the back of the mouth | Wisdom tooth treatment |
| Dry mouth | Sticky mouth, worse in the morning or with some medicines | More water, sugar-free gum, reviewing medicines with your doctor |
| Dentures | Smell from the denture itself | Cleaning the denture daily and leaving it out at night |
What happens at your visit
- History. When it’s worst, what you’ve tried, your medicines and any reflux, sinus or throat problems.
- Examination. Our dentist checks the teeth, gums, tongue, old fillings and any dentures, and measures the gums where gum disease is suspected.
- Treatment. Cleaning or deep cleaning, repairing decayed teeth or leaking fillings, and treating any gum disease.
- Your routine. We show you how to clean your tongue and between your teeth with the right size of interdental brush.
- Review. We check how things have improved after a few weeks.
What helps at home
- Brush twice a day for two minutes, including along the gum line.
- Clean between your teeth once a day with floss or interdental brushes.
- Clean the back of your tongue every morning.
- Drink plenty of water, especially if your mouth feels dry.
- Cut down on smoking and tobacco, which cause bad breath and gum disease.
- Clean dentures every day and take them out at night.
When to see a doctor
If your teeth, gums and tongue are healthy and the smell continues, it may come from the nose, sinuses, tonsils or stomach. We’ll tell you if that’s likely and suggest seeing your doctor.
What affects the fee
Whether a routine clean or deep cleaning is needed, how many teeth need fillings or repairs, and whether any old crowns or fillings are replaced. You get the fee after the examination.
Questions patients ask us
What causes bad breath?
In most people, bacteria in the mouth break down food and dead cells and release sulphur gases. They live on the back of the tongue, in gum pockets, in tartar and around decayed teeth or leaking fillings. Dry mouth, smoking, onions, garlic and some medicines make it worse.
Can bad breath come from the stomach?
Less often than people think. Acid reflux, sinus or tonsil problems and some medical conditions such as uncontrolled diabetes can cause it, but the mouth is the source in most cases. If your teeth, gums and tongue are healthy and the smell persists, we'll suggest seeing your doctor.
Why do I have bad breath even after brushing?
Brushing doesn't reach between the teeth, under the gum line or the back of the tongue, where most odour comes from. Gum disease and tartar also need professional cleaning. Cleaning between your teeth and your tongue every day usually makes a big difference.
Can bad breath be cured permanently?
When it comes from the mouth, yes, in most cases, by treating the cause, such as gum disease, decay or tartar, and keeping up a daily routine. Morning breath is normal and goes with brushing and breakfast.
Do mouthwashes cure bad breath?
They mask it for an hour or two. Some help as part of gum treatment, but they don't replace cleaning. Alcohol-based mouthwashes can dry the mouth and make breath worse later.
How can I tell if I have bad breath?
It's hard to judge your own breath. Lick the back of your wrist, let it dry and smell it, or ask someone you trust. A white or yellow coating on the back of the tongue is also a sign.
Why does my child have bad breath?
Usually from a coated tongue, food stuck between teeth, mouth breathing or a blocked nose, or enlarged tonsils. Decay in milk teeth can also cause it. Our paediatric dentist can check, and Dr. Sunisha Arora, our paediatrician, can look at nose and throat causes.
Sources
NHS: bad breath ↗ADA MouthHealthy: bad breath ↗Last updated 14 October 2026. This page explains options in general terms; your own plan comes from an examination.