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Bad breath

Halitosis is the medical name for bad breath. It describes an unpleasant smell in the breath which is detectable by other people.

Most of us worry about having bad breath at some point. While it's not dangerous, it is embarrassing, especially as as we get used to our own odours and often don't know we have it.

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What is halitosis?

Halitosis (bad breath) means that you have an unpleasant smell on your breath that other people notice when you speak or breathe out.

The exact number of people with halitosis is not known, but it is common. In some countries, studies have found as many as half of the population have problems with halitosis. In others the frequency is much less.

Types of halitosis

Halitosis can be:


Halitosis can be normal (physiological) in certain circumstances. This includes:

  • In the morning when you first wake up (morning breath).

  • If you smoke.

  • After eating certain foods - for example, garlic, onions, spices, cabbage, sprouts, etc.

  • After drinking a lot of alcohol.

  • Fasting, being on a crash diet or a low-carbohydrate diet.


This means there is a problem causing it. This is usually a problem in the mouth, but it can be coming from other sources, or caused by a specific illness or medical condition.


In this case, the person doesn't actually have halitosis. Nobody else can smell it but the person becomes very anxious about it. An extreme version of this is called halitophobia, the fear of bad breath. Some people think they have bad breath when they do not, and nobody else can smell it. This can result in odd behaviour to try to minimise what they think of as their halitosis. For example, they may cover their mouth when talking, avoid or keep a distance from other people, or avoid social occasions. People with halitophobia often become fixated with teeth cleaning and tongue cleaning and frequently use chewing gums, mints, mouthwashes and sprays in the hope of reducing their distress. Treatment from a psychologist may help.

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What causes halitosis?

Most of the time, it comes from a problem in your mouth, usually a problem with your teeth or a poor oral hygiene regime. It may be due to gum or teeth problems, food particles festering between your teeth, or germs on your tongue. Occasionally it's from a problem at the back of your mouth in your tonsils. (Often parents are aware their kids have tonsillitis because of the way their breath smells.)

In some people it can come from other sources. Problems in the nose or reflux of acid from the stomach may cause halitosis. Some medicines may cause it, as may certain diets. Some illnesses can cause typical breath odours. Learn more in the separate leaflet called Common Causes of Bad Breath.

How can you tell if you have halitosis?

A main problem with halitosis (bad breath) is that often the only person not to notice it is the person affected. You become used to your own smell and do not tend to notice your own bad breath.

Often, the only way to know about it is if a person comments on it. However, most people are too polite to comment on another person's bad breath. You may have to rely on a family member or a close friend to be honest and tell you if you have bad breath.

Perhaps you could ask your dentist next time you have a check-up. A dentist will normally be able to say if you have bad breath. Gum disease is a common cause of halitosis and a dentist will be able to advise on treatment if you have gum disease.

Some people suggest a simple test which you can do yourself to detect bad breath. Lick the inside of your wrist. Wait a few seconds for the saliva to dry. Then smell the licked part of the wrist. If you detect an unpleasant smell, you are likely to have bad breath.

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When to seek further help

If you have done everything you can in terms of the oral hygiene measures discussed in this leaflet and still have halitosis then see a dentist first, and then your doctors if the dentist does not identify any problems. You should also see a doctor if you have bad breath associated with other symptoms, such as acid reflux or sinus pain.

Who should I consult about halitosis?

You can see either a doctor or a dentist. Usually a dentist would be the first port of call, as they can do a thorough check of your teeth and gums, which are the most common source of the problem. If the dentist can't find a cause in your mouth, he or she may suggest you consult a doctor.

Will I need any tests?

For most people this won't be necessary. You would have an examination of your mouth by your dentist. In some cases the dentist may suggest an X-ray to look further at your teeth. Your doctor may ask about other symptoms and examine you to look for other causes if the dentist cannot find a cause. If this is the case, you may need some tests to assess if you have a less common cause of halitosis. This might include:

  • Blood tests.

  • An examination of the inside of your nose with a tube (nasoendoscopy).

  • An examination of your gullet and stomach (gastroscopy).

  • A breath, blood or stool test for the germ Helicobacter pylori, which sometimes is a cause.

How to get rid of halitosis

Good oral hygiene

This means regularly and effectively brushing your teeth, including and cleaning between teeth.

These routine daily procedures are usually sufficient to look after your teeth and to treat or prevent halitosis. However, if you still have bad breath coming from your mouth then the following extra measures may help cure the problem.


Consider using a mouthwash each day. Chemicals in the mouthwash aim to kill germs (bacteria) and/or neutralise any chemicals that cause halitosis. It is difficult to advise on which mouthwash is the most effective. A number of clinical trials have shown that various ingredients are good at reducing bad breath. These include chlorhexidine, cetylpyridinium chloride, chlorine dioxide, zinc chloride and triclosan. The various mouthwashes that you can buy usually contain one or more of these ingredients, plus various other ingredients.

Note: some people are reluctant to use a chlorhexidine-containing mouthwash long-term. This is because it has a bad taste, can give rise to a burning sensation in the mouth if used too frequently, and can cause (reversible) staining of the teeth or occasionally some temporary darkening of the tongue. Also, some mouthwashes contain alcohol as one of their ingredients. There is some concern that long-term use of alcohol-containing mouthwashes may be a risk factor in the development of mouth cancer. Also, young children should not use a mouthwash if they may swallow it.

Tongue cleaning

Consider cleaning the back of your tongue each day. Some people do this with a soft toothbrush dipped in mouthwash (not toothpaste). An easier and better way is to buy a special plastic tongue scraper from a pharmacy. You need to place it as far back as you can and then gently scrape forward to clear the tongue of any coating. Some studies suggest that tongue scrapers or cleaners are slightly more effective than toothbrushes as a means of controlling halitosis.

Chewing gum

Some people chew sugar-free gum after each meal. It is not clear how well gum helps to reduce bad breath but chewing gum increases the production of saliva. Saliva helps to flush the mouth to help clear any debris remaining from the meal.

Food and drink

Sugars and sugary foods in the mouth are the main foods that germs (bacteria) thrive on to make acid which can contribute to tooth decay. Acidic foods and drinks are also a main factor in tooth erosion. So, some tips:

  • Limit the amount of sugary foods and drinks that you have. In particular, don't snack on sugary foods.

  • Try to reduce the amount of acid in contact with your teeth. So, limit fizzy drinks (including fizzy water) and fruit juices, as these tend to be acidic. Perhaps just limit yourself to one fizzy or fruit juice drink a day. Otherwise, choose drinks that are much less acidic, such as still water, and milk, tea, or coffee (without sugar).

  • Drink any acidic drinks, such as fizzy drinks and fruit juices, quickly - don't swish them around your mouth or hold them in your mouth for any period of time.

  • Brush your teeth at least an hour after eating or drinking anything - especially acidic foods and drinks. (See above for reasons.)

  • Likewise, do not brush your teeth within an hour of being sick (vomiting), as stomach acid will be part of the vomit.

  • When giving children medicines, such as Calpol®, use the sugar-free versions wherever possible.

Stop smoking

If you smoke, try to stop. Smoking or using other oral tobacco products increases the risk of developing gum disease as well as causing halitosis because of chemicals left in the mouth.

If you have dentures and have halitosis

You may not be cleaning them properly. Ask your dentist for advice on cleaning dentures.

What treatment will I need if the halitosis doesn't go away?

This will naturally depend on the cause. For example, if it turns out you have nasal polyps, you might be prescribed a steroid nasal spray, or have an operation. If you have acid reflux, you may prescribed medicines such as proton pump inhibitors (PPIs). You may be prescribed antibiotics if you have an infection, etc.

What's good oral hygiene?

The main treatment of halitosis coming from within the mouth is good oral hygiene. Aim to get into a regular habit of good oral hygiene - in particular, teeth brushing and cleaning between teeth.

Teeth brushing

Brush your teeth at least twice a day. Use a soft-tufted brush and a toothpaste that contains fluoride. The head of the brush should be small enough to get into all the areas of the mouth. Spend at least two minutes brushing, covering all areas (the inside, outside and biting areas of each tooth). Pay particular attention to where the teeth meet the gum. Get a new toothbrush every 3-4 months. Studies suggest that powered toothbrushes remove plaque and debris better than manual brushes.

Ideally, brush your teeth either just before eating, or at least an hour after eating. The reason for this is to help prevent tooth erosion. Many foods contain acids. In particular, fizzy drinks (including fizzy water) and fruit juices. After your teeth are exposed to acid, the enamel is a little softened. But, the action of calcium and other mineral salts in the saliva can help to counteract and reverse this softening. Therefore, do not brush teeth immediately after eating when the enamel tends to be at its softest; in particular, after eating or drinking acidic foods and drinks. It is best to wait at least an hour after eating or drinking anything before brushing.

Cleaning between teeth

Clean between your teeth after brushing once a day, but ideally twice a day. This is to remove plaque from between teeth. Dental floss is commonly used to do this. It may be that small interdental brushes are more effective, but studies have not yet shown this convincingly. The aim is to clean the sides of the teeth where a toothbrush cannot reach. Also, to clear the spaces between teeth (the interdental spaces) of debris. Some people who have not cleaned between their teeth before are surprised as to how much extra debris and food particles can be removed by doing this in addition to brushing.

If you are not sure how to clean between your teeth then ask your dentist or dental hygienist. Briefly: normal floss looks a bit like cotton thread. Cut off about 40 cm. Wind the ends round your middle fingers of each hand. Then grab the floss between the thumbs and first finger to obtain a tight 3-4 cm section which you can pull between teeth. Gently scrape the floss against the sides of each tooth from the gum outwards. Use a fresh piece of floss each time.

Some people prefer floss tape which slides between teeth more easily than normal floss. Also, some people use disposable plastic forks with a small length of floss between the two prongs. These may be easier to hold and manipulate. However, they are expensive. Some people use sticks, or small interdental brushes to clean the space between the teeth.

The gums may bleed a little when you start to clean between your teeth. This should settle in a few days. If it persists, see a dentist, as regular bleeding may indicate gum disease.

Have regular dental checks at intervals recommended by your dentist (normally at least once a year). A dentist can detect build-up of plaque and remove tartar (calculus). Early gum disease can be detected and treated to prevent it from getting worse.

Further reading and references

  • Phillips IR, Shephard EA; Trimethylaminuria, University of Washington, 2007 (updated 2011)
  • Yaacob M, Worthington HV, Deacon SA, et al; Powered versus manual toothbrushing for oral health. Cochrane Database Syst Rev. 2014 Jun 17;(6):CD002281. doi: 10.1002/14651858.CD002281.pub3.
  • Poklepovic T, Worthington HV, Johnson TM, et al; Interdental brushing for the prevention and control of periodontal diseases and dental caries in adults. Cochrane Database Syst Rev. 2013 Dec 18;(12):CD009857. doi: 10.1002/14651858.CD009857.pub2.
  • Kuo YW, Yen M, Fetzer S, et al; Toothbrushing versus toothbrushing plus tongue cleaning in reducing halitosis and tongue coating: a systematic review and meta-analysis. Nurs Res. 2013 Nov-Dec;62(6):422-9. doi: 10.1097/NNR.0b013e3182a53b3a.
  • Kapoor U, Sharma G, Juneja M, et al; Halitosis: Current concepts on etiology, diagnosis and management. Eur J Dent. 2016 Apr-Jun;10(2):292-300. doi: 10.4103/1305-7456.178294.
  • Reidy JT, McHugh EE, Stassen LF; A review of the role of alcohol in the pathogenesis of oral cancer and the link between alcohol-containing mouthrinses and oral cancer. J Ir Dent Assoc. 2011 Aug-Sep;57(4):200-2.
  • Halitosis; NICE CKS, September 2019 (UK access only)

Article history

The information on this page is written and peer reviewed by qualified clinicians.

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