Bad Breath Explained
Bad breath is common, usually fixable and rarely a sign of anything serious. The catch is that most remedies on the chemist's shelf only cover it up, so here is where it really comes from and what makes a lasting difference.
What Causes Bad Breath and How Can a Dentist in Edinburgh Help?
Most bad breath starts in the mouth, usually from bacteria on the back of the tongue, gum disease or a dry mouth, and mouthwash only hides it for a while. Fixing it means cleaning the tongue and between the teeth properly and treating any gum problem. At Comely Bank Dental in Edinburgh, a 30-minute hygiene visit is £90, and it's a good place to find the cause.
What Actually Causes Bad Breath?
In most people, bad breath starts in the mouth rather than the stomach. Bacteria living on the tongue, between the teeth and under the gum line break down proteins from food, dead cells and blood, releasing sulphur gases as they go. Those gases are what other people notice.
The most common sources are:
- A coated tongue, especially towards the back
- Gum disease, where bacteria collect in pockets around the teeth
- A dry mouth, from medicines, mouth breathing, alcohol or not drinking enough
- Food traps, such as gaps under old fillings, decay or a partly erupted wisdom tooth
- Dentures that aren't cleaned well or are worn overnight
- Smoking, which dries the mouth and adds its own smell
Less often, the cause lies outside the mouth: tonsil stones, the nose and sinuses, or occasionally a medical condition.
Why Is the Tongue So Often the Problem?
The top of your tongue isn't smooth. It's covered in tiny folds and projections that hold on to bacteria and debris, and the back third is barely disturbed by eating or brushing. A white or yellowish coating there is one of the most common sources of bad breath we see.
Cleaning it takes less than a minute:
- Use a tongue scraper, or a toothbrush with a tongue-cleaning surface on the back.
- Stick your tongue out, breathe out through your mouth and start as far back as is comfortable.
- Draw the scraper forward with light pressure, rinse it and repeat a few times.
- Do it once a day, ideally at night.
If you have a strong gag reflex, start a little further forward and work back gradually. Don't scrub: the aim is to lift the coating, not make the tongue sore.
Worried About Your Breath?
Book a hygiene visit with Katie. We'll look for the source, clean thoroughly and show you what to change at home.
Could It Be Your Gums or Teeth?
Gum disease is the other big cause. When plaque sits along the gum line, the gums become inflamed and pull away slightly from the teeth, leaving pockets where bacteria thrive and a brush can't reach. The smell from those pockets is distinctive and doesn't go away with brushing alone.
Signs your gums may be involved:
- bleeding when you brush or clean between your teeth
- a bad taste that keeps coming back
- gums that look red or puffy, or seem to be shrinking back
- teeth that feel loose or have started to drift
Gum disease is often painless, which is why many people don't know they have it. It's very treatable, especially early, and treating it usually improves the breath noticeably. Our page on gum disease treatment explains more.
Other dental causes include decay, broken or leaking fillings, crowns with a gap at the edge, and wisdom teeth only partly through the gum, which trap food and can become infected.
Dry Mouth, Morning Breath and What You Eat
Saliva is your mouth's natural rinse. It washes away food and bacteria, so anything that reduces it tends to make breath worse.
Morning breath is normal. Saliva flow drops while you sleep, bacteria multiply, and the smell usually clears after breakfast and brushing. It's only worth looking into if it lasts all day.
A dry mouth during the day can come from:
- medicines, including some antidepressants, antihistamines and blood pressure tablets
- breathing through your mouth, for example with a blocked nose
- alcohol, caffeine and smoking
- not drinking enough water
Don't stop a prescribed medicine on your own. If you think it's drying your mouth, mention it to us and to your GP.
Diet matters too. Garlic, onions and some spices release sulphur compounds that are absorbed into the blood and breathed out through the lungs, so brushing won't shift them for a while. Very low-carbohydrate diets and long gaps without eating can cause a distinctive ketone smell, which also comes from the lungs.
Tonsil Stones and Causes Beyond the Mouth
Tonsil stones are small, pale yellow or white lumps that form in the creases of the tonsils from trapped debris and bacteria, and they can smell strongly. They're harmless, and gargling with salt water after meals can help. Don't dig at them with anything sharp. If they keep coming back or your throat is often sore, see your GP.
Other causes are less common:
- Nose and sinuses: sinus infections and post-nasal drip can give a stale smell, usually with congestion.
- Reflux: occasionally contributes, typically alongside heartburn or a sour taste.
- Medical conditions: poorly controlled diabetes can give a sweet, fruity smell, and kidney or liver disease can rarely affect the breath. These come with other symptoms and are seldom the first clue.
If your mouth is healthy and the smell persists, that's the point to involve your GP.
How Can You Tell If You Have Bad Breath?
It's surprisingly hard to judge your own breath. Your nose gets used to smells that are always there, and breathing into cupped hands isn't reliable. Better checks:
- Lick the back of your wrist, wait a few seconds and smell it.
- Clean between your back teeth with floss or an interdental brush and smell it.
- Gently scrape the back of your tongue and check the scraper.
- Ask someone you trust to tell you honestly, at different times of day.
Clues include a persistent bad taste, a visible coating on the tongue, or people seeming to step back during conversation.
Some people are convinced they have bad breath when nobody else can detect it. If that sounds like you, an honest opinion from a dental professional can be a real relief, and we're happy to give one tactfully.
What Genuinely Works?
No single product fixes bad breath. What works is removing bacteria where they live and keeping saliva flowing:
- Brush twice a day for two minutes with a fluoride toothpaste, including along the gum line.
- Clean between your teeth once a day. Interdental brushes suit most adults where they fit; floss or tape works for tight gaps.
- Clean your tongue daily.
- Keep your mouth moist. Sip water through the day and chew sugar-free gum after meals.
- Look after dentures and aligners. Clean them daily, and take dentures out overnight unless advised otherwise.
- Stop smoking. Your breath and your gums will both benefit.
- Keep up regular hygiene visits so tartar is removed and gum problems are caught early.
Many people notice a difference within a couple of weeks of cleaning their tongue and between their teeth properly. If you don't, there's usually a specific cause to find.
What Doesn't Work, or Only Covers It Up?
Mints, sprays and strong mouthwash mask odour for a short time but do nothing about the bacteria producing it. Sugary mints add to the risk of decay.
Alcohol-based mouthwashes can dry the mouth, which may make breath worse later in the day.
Rinsing instead of cleaning doesn't work. A rinse can't break up plaque between the teeth or the coating on the tongue.
That said, mouthwashes containing cetylpyridinium chloride or zinc can reduce odour-producing bacteria for longer, and are a reasonable extra alongside a good routine. Chlorhexidine is effective but can stain teeth and alter taste, so keep it for short courses on professional advice. Use any mouthwash at a different time from brushing, such as after lunch, so you don't rinse away your toothpaste's fluoride.
Charcoal products and 'breath detox' kits have little good evidence behind them, and abrasive charcoal pastes can wear enamel.
When Should You See a Dentist or GP?
See us first if you notice bleeding gums, a recurring bad taste, a tongue coating that returns despite cleaning, loose teeth, food trapping, a broken filling or denture problems.
See your GP if your teeth and gums are healthy but the smell persists, or you have sinus symptoms, frequent tonsil stones or regular heartburn. Get urgent medical advice for a sweet or fruity smell on the breath alongside thirst, passing more urine than usual, nausea or feeling unwell.
See a dentist or GP promptly about any mouth ulcer, red or white patch, or lump that hasn't healed within three weeks.
How We Help with Bad Breath in Edinburgh
At Comely Bank Dental, a hygiene visit with Katie Ventisei, our dental hygienist and therapist, is the natural place to start. A 30-minute visit is £90; with heavier build-up, we may suggest a longer visit at £135. We clean thoroughly, check your gums, look for the source and show you exactly what to change at home. If there's a dental cause, such as a leaking filling or gum disease, we'll explain the options and fees first.
Adults are seen privately, and the children of our dental plan members under the NHS. If you're new to us, our new patients page explains how to register, or you can book online.
Questions
This guide is general information, not a diagnosis. A dentist needs to examine you to say what is right for your teeth.