Bad breath
Bad breath is an unpleasant smell coming from your mouth. It’s usually caused by a build-up of plaque or bacteria. There are lots of things you can try to get rid of bad breath. But if they don’t work, your dentist can help you figure out the likely cause and get treatment.
About bad breath
Bad breath is also known as halitosis (pronounced hal-i-toe-sis). It’s a common condition that can come and go at any time for no apparent reason. There are lots of reasons you might get bad breath, like eating strong smelling foods, taking certain medications, or having an underlying health condition. So in order to eliminate bad breath, it’s important to get to the root cause of the problem.
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Bad breath causes
There are lots of things that can lead to bad breath, such as:
Not cleaning your teeth properly
When you brush and floss your teeth, it helps to remove plaque and tiny pieces of trapped food from your mouth. But if you don’t clean your teeth properly, decaying food particles and plaque can start to build up in between your teeth and gums, causing a bad smell.
Strong-smelling food and drinks
Food and drinks such as onions, garlic, spices and alcohol can linger on your breath for a long time. This is because chemicals in these foods enter your bloodstream during digestion, before passing to your lungs and being exhaled via your mouth.
Problems with your teeth or gums
Dental conditions like tooth decay , a tooth infection, mouth sore or gum disease can all cause bacteria to build up inside your mouth and lead to bad breath.
Dry mouth
Dry mouth (known by doctors as xerostomia), happens when your mouth doesn’t produce enough saliva. But saliva is essential for cleaning away particles that cause bad breath. You could develop dry mouth because of a salivary gland condition, certain medications, only breathing through your mouth, smoking, dehydration or undergoing radiotherapy or chemotherapy.
Mouth, nose and throat conditions
Problems that affect your mouth, nose and throat can all cause a bad smell to develop in your mouth. This could be something like a sinus infection, tonsillitis, or postnasal drip (when mucus runs from your nose to your throat, for example because of allergies or the flu).
Health conditions
Sometimes, bad breath may be a sign of an underlying health condition, such as diabetes, gastro-oesophageal reflux disease (GORD), kidney disease, liver disease or some cancers of the throat and mouth.
Medication
Some medicines such as biphosphonates, lithium, melatonin, nicotine lozenges and amphetamines can come with the unwanted side-effect of bad breath. If you take medication that you think might be causing your bad breath, speak to your doctor to find out if there’s an alternative.
Smoking
Smoking tobacco products in themselves can leave an unpleasant smell in your mouth. But smokers are also more likely to develop gum disease and dry mouth, both of which contribute to bad breath.
Dieting
Fasting, crash dieting or following a keto or low-carbohydrate diet can all cause an odd smell to develop on your breath. This is because chemicals called ketones are released when fat is broken down, which you then breathe out.
How to get rid of bad breath
Keeping your entire mouth clean can help to fix bad breath (halitosis). This includes cleaning your teeth, gums, tongue and the spaces in between your teeth. Try these tips.
- Brush your teeth and gums with a fluoride toothpaste twice a day for two minutes.
- Gently clean the surface of your tongue with a brush or tongue cleaner before bed.
- Spit instead of rinsing after brushing, so you don’t wash away the fluoride in your toothpaste.
- Use floss or interdental brushes at least once a day before you brush.
- Use an antimicrobial mouthwash.
- If you wear braces, dentures, or a retainer, make sure to clean them regularly.
- Avoid eating strong-smelling foods like onions and garlic.
- Drink plenty of water – it helps wash away food and bacteria that cause bad breath.
- Visit your dentist and hygienist for regular check-ups and cleaning.
- Chew sugar-free gum – it helps produce saliva which stops your mouth from drying out.
Symptoms of bad breath
The main symptom of bad breath (halitosis) is an unpleasant smell in your mouth. But if your bad breath is caused by an underlying health condition, you might have other symptoms too. This could include things like a very dry mouth, a blocked nose, losing your sense of smell, or losing weight.
Diagnosis of bad breath
If your breath isn’t getting better after a few weeks of self-help measures, see your dentist. They’ll ask you about your lifestyle and dental hygiene habits, any medication you might be taking, and whether or not you have any other symptoms too.
Your dentist will do a thorough check-up of your teeth, gums, and tongue to see if you have any underlying dental conditions. They’ll also ask you to breathe out through your mouth and nose separately so they can smell your breath and try to figure out where the odour might be coming from. So it’s a good idea not to smoke, eat or drink very smelly foods, wear strong fragrances or brush your teeth before your appointment.
If your dentist can’t get to the bottom of what’s causing your bad breath or thinks it could be down to a medical condition or medication, they may suggest you see your GP.
Bad breath treatment
If you do need further halitosis treatment, the type of treatment you’ll be offered will depend on what’s causing it. For example if your bad breath is due to:
- a build-up of plaque or gum disease, a deep clean may be helpful
- dry mouth, your dentist may suggest some lifestyle changes and that you use an artificial saliva product
- a sinus infection, your doctor may recommend a nasal spray, decongestants or medication
Your dentist or doctor will advise on the best course of action for you.
Prevention of bad breath
ITaking good care of your teeth and gums is the best way to stop bad breath.
For more information on this, see our self-help section above.
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- • Acute sinusitis. BMJ Best Practice. bestpractice.bmj.com, last reviewed June 2024
