Bad Breath: Causes and Cures


Bad breath (the medical term for which is halitosis) is an embarrassing but incredibly common oral health problem. In fact, it is estimated that bad breath impacts more than 50% of the general population around the globe.1 Yet many people who suffer from halitosis are completely unaware of their condition until it’s pointed out by someone else, often leading to uncomfortable social exchanges.

There are an immense variety of products on the market that promise to eliminate bad breath : Everything from mouthwashes to chewing gum, breath mints, and dissolving tongue strips. In most cases, however, these products only provide a temporary solution. Foul smelling breath can be caused by a number of underlying conditions; only by treating the root cause can chronic halitosis be stopped for good.

Experiencing a serious case of bad breath that won’t go away despite your best efforts? See a dentist as soon as possible to rule out more serious oral health issues.


What Causes Bad Breath?

We all know that bad breath can develop if you don’t brush your teeth – but do you know what’s happening on a molecular level? Bad breath takes place when volatile compounds are formed and released orally, whether or not those compounds originated in the mouth. These volatile substances may contain sulfur- or nitrogen-containing compounds, amines, alcohols, or ketones, all of which have a particular molecular structure that your brain registers as an unpleasant smell.2

The majority (90 percent) of halitosis cases originate in the mouth; the other 10 percent may be caused by gastrointestinal, respiratory, or other non-oral disease.1 If you experience bad breath only on occasion, it’s probably nothing to be concerned about: Most likely, it has to do with something you ate, an lapse in brushing or flossing, or simply a lack of flowing saliva (which plays a major role in ‘morning breath’). Luckily, adhering to proper dental hygiene habits is typically sufficient for combatting the average case of halitosis.


The following are some of the most common causes of bad breath: 


  • Poor Oral Hygiene: If teeth are not brushed and flossed regularly, particles of food will tend to remain lodged between them. As these particles begin to decay, they release molecular compounds that lead to bad breath. In addition, microbial deposits that build up on the tongue function as bacteria-rich harbors; this is another common source of unpleasant-smelling breath. As long as good oral hygiene is put into practice – including brushing or scraping the tongue and regular flossing – these instances of halitosis will be reduced.
  • Certain Foods: Foods such as garlic, onions, pickles, radish, and certain spices and condiments contain odor-causing compounds. These compounds are absorbed into the bloodstream and later released when exhaled. Halitosis caused by food is temporary, typically lasting only a few hours.1
  • Dental Problems: Certain dental problems can also lead to bad breath. Gingivitis, periodontal disease, cavities, dry socket, oral ulceration, and pericoronitis are possible causes.1 If you notice inflammation of your gums or are experiencing any tooth pain or pain when chewing along with bad breath, visit your dentist to address any possible dental conditions.
  • Tobacco and Alcohol: Tobacco and alcohol both influence bad breath by introducing volatile compounds into the bloodstream. In addition, tobacco products tend to dry out the mouth, making bad breath even worse – since saliva is what keeps your mouth flushed and clear of residual food particles, insufficient saliva production has a considerable impact on halitosis.
  • Dry Mouth: Caused by certain medications, health conditions, or excessive alcohol, tobacco, or caffeine consumption, dry mouth is indicated by a decrease in natural saliva production. As mentioned, saliva production is incredibly important to oral health: It keeps your mouth clear of debris and provides disease-fighting substances that help to ward off cavities and other infections.3 A lack of saliva means more food particles will decay in the mouth and the likelihood of other dental issues is increased, thereby increasing the risk for bad breath. This is another reason why many individuals experience ‘morning breath’ – simply because dry mouth can occur overnight due to the lack of hydration and saliva production during sleep.


Non-Oral Health Conditions

It is possible for bad breath to be caused by an associated health condition that plays a role in the release of volatile molecules on the breath. Dieting, snoring, stress, age, and hormonal changes – including menstruation – can also impact your breath. 

The following diseases, among others not listed here, have been known to cause or worsen halitosis:4


  • Respiratory tract infection
  • Tonsillitis
  • Sinusitis
  • Gastrointestinal disease
  • Gastroesophageal reflux disease (GERD)
  • Hepatic failure
  • Renal (kidney) failure
  • Diabetic ketoacidosis
  • Leukemia 
  • Acute fever


How Can I Prevent or Reduce Bad Breath?


The majority of halitosis cases are easy to prevent. Implementing healthy dental habits, avoiding odor-causing foods, and regularly visiting your dentist for professional cleanings and examinations will all help keep your breath fresh. However, if bad breath persists despite these preventative measures - and underlying health problems and diseases have been ruled out - there are a few additional measures you can take to mitigate the problem:

  • Use ADA-Approved Oral Hygiene Products: When purchasing toothpaste, mouthwash, and other oral health products, make sure they’ve been marked with the ADA Seal of Acceptance. Use fluoride-containing toothpaste to brush at least twice per day; floss at least once per day or use an interdental cleaner to remove food particles from between teeth.5
  • Chew Sugar-Free Gum: Look for sugar-free chewing gum marked with the ADA Seal of Acceptance to mask bad breath and stimulate saliva production. However, avoid sugary mints or sugar-containing gum, which can increase the risk for tooth decay.5
  • Try Tongue Scraping: Don’t just use a toothbrush to clean your tongue. A specially-designed tongue scraper that removes the coating of bacteria accumulated on the tongue can reduce bad breath-inducing sulfur compounds by up to 75 percent. Toothbrush bristles, on the other hand, only reduce these compounds 45 percent according to a comparative clinical trial.6
  • Keep Dentures, Retainers, and Mouthguards Clean: If you wear dentures or have a bridge, clean the device thoroughly at least once a day – and make sure to remove it before going to sleep. Use the same cleaning protocol for dental retainers and mouth guards, both of which can harbor odor-inducing organisms and bacteria.
  • Stay Hydrated: The best way to avoid dry mouth and keep saliva flowing is by staying hydrated throughout the day. Drink plenty of water and try to cut back on caffeine and alcohol, both of which can be dehydrating. Remember to consume a large glass of water before bed to help prevent morning breath.
  • Replace Your Toothbrush: When your toothbrush starts to get frayed or the bristles appear worn, it's time to get a new toothbrush. An old toothbrush won’t do a sufficient job in keeping teeth clean and clear of debris. The American Dental Association recommends replacing your toothbrush every three to four months.7


Final Thoughts

Bad breath happens. Don't stress! While it may be humiliating, most cases of halitosis can be remedied with simple changes to your lifestyle and oral health routine. However, if the problem persists or is accompanied by other symptoms of dental disease, it is recommended you visit a dentist  as soon as possible to rule out more serious conditions. 


Additional Resources

Looking for more information? Brush up on dental care basics:


Concerned about your breath?  Find a dentist in your area.




1. Aylıkcı, Bahadır Uğur, and Hakan Colak. “Halitosis: From Diagnosis to Management.” Journal of Natural Science, Biology, and Medicine, Medknow Publications & Media Pvt Ltd, Jan. 2013, 

2. Kapoor, Uditi, et al. “Halitosis: Current Concepts on Etiology, Diagnosis and Management.” European Journal of Dentistry, Medknow Publications & Media Pvt Ltd, 2016, 

3. “Halitosis.” Mouth Healthy, American Dental Association,

4. Armstrong, Brenda L, et al. “Halitosis: A Review of Current Literature.” UMN School of Dentistry,

5. “What You Should Know about Bad Breath.” The Journal of the American Dental Association, vol. 134, no. 1, 2003, p. 135., doi:10.14219/jada.archive.2003.0027.

6. Pedrazzi V, Sato S, de Mattos Mda G, Lara EH, Panzeri H. Tongue–cleaning methods: A comparative clinical trial employing a toothbrush and a tongue scraper. J Periodontol. 2004;75(7):1009–1012.

7. “Oral Health Topics - Toothbrushes.” ADA, American Dental Association,

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