Bad breath: how common is it?


Halitosis (bad breath) is an unpleasant odour coming from the mouth that may originate from an oral or non-oral sources. It can be unpleasant enough to cause personal embarrassment. The reported prevalence estimates range from 2.4 to 78% with the American Dental Association reporting that 50% of American adults suffer.

The main aim of this review was to assess the prevalence of halitosis in adults and adolescents.


Searches were conducted in the Medline, Web of Science, Scopus, and SciELO databases. Two reviewers independently screened the studies. Original observational studies published in English, Spanish, French, and Portuguese which reported the prevalence or data that allowed the calculation of prevalence of halitosis in adolescents and adults were considered.  Two reviewers assessed study quality using the Joanna Briggs Institute checklist for prevalence and incidence studies.

Data was extracted by two reviewers with halitosis assessment (self-reported, organoleptic test, VSC test) being noted and prevalence rates collected or calculated. The estimated global prevalence of halitosis was calculated using fixed- and random-effect models.


  • 13 studies involving a population of 384,830 individuals were included.
  • 9 studies were considered to be at low risk of bias and 4 at high risk.
  • The estimated prevalence halitosis in the general population = 31.8% (95%CI; 24.6–39.0%)
  • Prevalence in developed countries = 29.0% (95%CI; 21.2–36.8) and
  •  low-middle income countries = 39.8% (95% CI; 21.1–54.9)
  • 60% of the heterogeneity was explained by socioeconomic status of the country where the study was conducted.
  • The method of halitosis detection employed (self-reported v clinical) did not explain the variability between studies.
  • Statistical testing suggested publication bias.


The authors concluded: –

Our results demonstrated that the estimated prevalence of halitosis was 31.8%, with high heterogeneity between studies. The results suggest a worldwide trend towards a rise in halitosis prevalence.


This interesting review provides a good overall assessment of the prevalence of halitosis. The authors highlight that while both oral and non-oral sources for halitosis are investigated 80-90% of case are attributed to an oral cause. The suggest that higher rates of periodontal disease in low-middle income countries may be linked to the higher overall prevalence of halitosis.  They also highlight higher prevalence of halitosis noted in studies published after 2007 speculating that this may be due to changes in dietary patters with an increase in the consumption of alcohol and in the use of spices as flavouring in foods. Although there may also be greater attention being paid to halitosis. Given the subjectivity of self-assessed halitosis and organoleptic testing it is interesting that the method used to assess halitosis assessment did not impact on its prevalence.


Primary paper

Silva MF, Leite FRM, Ferreira LB, Pola NM, Scannapieco FA, Demarco FF, Nascimento GG. Estimated prevalence of halitosis: a systematic review and meta-regression analysis. Clin Oral Investig. 2017 Jul 4. doi:10.1007/s00784-017-2164-5. [Epub ahead of print] Review. PubMed PMID: 28676903.

Other references

Dental Elf- 29th Apr 2015

Mouthwashes and toothpastes can improve oral malodour

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Derek Richards

Derek Richards is a specialist in dental public health, Director of the Centre for Evidence-Based Dentistry and Specialist Advisor to the Scottish Dental Clinical Effectiveness Programme (SDCEP) Development Team. A former editor of the Evidence-Based Dentistry Journal and chief blogger for the Dental Elf website until December 2023. Derek has been involved with a wide range of evidence-based initiatives both nationally and internationally since 1994. Derek retired from the NHS in 2019 remaining as a part-time senior lecturer at Dundee Dental School until the end of 2023.

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