5 Reasons Dental Patients May Suffer from Halitosis

© dundanim / Adobe Stock

Halitosis is a concern for many dental patients. As a matter of fact, about 50% of the U.S. population suffers from halitosis. Halitosis can be put into two different categories − genuine halitosis or delusional halitosis.1

This article explores some causes of extraoral halitosis. But, first, a refresher on how halitosis is usually categorized is offered.

Delusional halitosis is further categorized into one of two categories, pseudo-halitosis or halitophobia. An estimated one-third of patients who seek treatment for halitosis fall into one of these two categories. Patients diagnosed with pseudo-halitosis are seemingly healthy yet complain of bad breath that only they have noticed. These patients also report that the bad breath occurs when their mouth feels dry, hot, or heavy, often reporting a persistent bad taste. Halitophobia patients also have no indication of bad breath from anyone except themselves; they are often obsessed with their breath.2

Genuine halitosis can also be broken down further into two groups, physiological halitosis and pathological halitosis. Physiological halitosis is your everyday run of the mill morning breath; we have all experienced this.

Pathological halitosis is broken into two more categories, intraoral causes and extraoral causes. Intraoral causes, such as periodontal disease, xerostomia, odontogenic infections, and mucosal lesions, account for 80% to 85% of the cases of halitosis. Intraoral causes can be managed by proper oral hygiene and treating infections and periodontal disease. Due to the multiple etiologies, some being unavoidable such as multiple medications, xerostomia seems to be the toughest issue to tackle when managing intraoral halitosis.1

Extraoral etiology should be considered when all intraoral possibilities have been addressed without resolution. Extraoral causes are often neglected because many dental professionals are unaware of the connection. It is important to explore the other possibilities as to help the patient find a resolution for their concerns. The following list includes some, but not all, the extraoral causes of halitosis.

1) Menstruation

The primary cause of halitosis is volatile sulfur compounds and hydrogen sulfide. This is true for intraoral causes as well as some extraoral causes. Studies show an increase in halitosis during the menstrual phase and a decrease in halitosis during the premenstrual phase. This change is attributed to the changes in hormones during the different menstrual phases.

Additionally, it was noted that changes in hormones increase gingivitis during menstruation, which is known to be a contributing factor to halitosis. The limitations of such studies include the association between stress, anxiety, and menstruation. Many women express increased stress and anxiety during menstruation; this is an important point because anxiety has also been linked with increased reports of halitosis.3 Anxiety sends our body into fight or flight mode. When we experience this rush of adrenaline, our hearts beat faster and our breathing increases, many people breath through their mouth when respiration increases, creating temporary xerostomia leading to halitosis.

2) Trimethylaminuria

Trimethylaminuria is a disorder that inhibits the body from breaking down trimethylamine. Trimethylamine has a very pungent odor, often described as rotting fish, rotting eggs, garbage, and urine. As the compound builds up in the body, it causes a strong odor in sweat, urine, and breath.

The etiology of the disorder is a mutation in the FMO3 gene. A normally functioning FMO3 gene assists in the making of an enzyme that has the job of breaking down nitrogen-containing compounds from diet, including trimethylamine. Trimethylamine is produced by bacteria in the gut during the digestion of certain proteins. The mutation of FMO3 enables the production of this enzyme. Normally, this enzyme converts the foul-smelling trimethylamine into another molecule that has no odor. Stress and diet may exacerbate the disorder.4

Management includes dietary restrictions along with activated charcoal as a supplement to absorb trimethylamine produced in the gut as well as riboflavin supplements to enhance residual FMO3 enzyme activity.5

3) Hypermethioninemia

Hypermethioninemia is a condition that prevents the proper metabolism of a particular amino acid, methionine. Most people with the condition show little to no signs of the condition. When symptoms are present, they include neurological problems, delays in motor skills, sluggishness, muscle weakness, unusual facial features, and their breath, sweat, or urine may smell like boiled cabbage.

The cause is attributed to mutations in the AHCY, GNMT, and MAT1A genes. It can also be associated with other metabolic disorders such as homocystinuria, tyrosinemia, and galactosemia. This is thought to be a rare condition; however, the number of individuals affected is unknown, because of the lack of symptoms.6

4) Agranulocytosis

Agranulocytosis is a condition where the patient has a critically low granulocyte (neutrophil) cell count. This condition can be acquired or inherited; it is estimated to affect 1 to 3.4 million people a year. Untreated, it can lead to septicemia and death.

There are a number of ways to acquire the condition. Some causes include chemotherapy, certain antibiotics, antithyroid and antipsychotic medications, exposure to toxic substances such as arsenic or mercury, aplastic anemia, and some autoimmune diseases.7 Patients with blood disorders, such as agranulocytosis, experience halitosis due to necrotic ulcers, stomatitis, infection, and blood decomposition from spontaneous bleeding.8,9

5) Bronchiectasis

Bronchiectasis is a condition that occurs when damage to the airway causes them to become widened, flabby, and scarred. Due to the damage to the airway, clearing mucus becomes difficult, resulting in an environment for bacteria to build up and grow. The build-up of mucus and bacteria leads to halitosis.

Bronchiectasis can be congenital or acquired. Congenital bronchiectasis is the result of the improper formation of the lungs during fetal development. Usually, damage to the lungs that result in bronchiectasis begins in childhood. Before vaccines, many children acquired it due to damage to their lungs from whooping cough and measles.

Additional conditions that raise the risk of bronchiectasis include immunodeficiency disorders, rheumatoid arthritis, Sjogren’s disease, and Crohn’s disease. There is currently no cure; however, with proper management, people have a good quality of life. Poor management can lead to heart and respiratory failure.10

As dental professionals, we are often met with concerns from patients about halitosis. This can be a difficult problem to manage because it can be multifactorial. Of course, considering most problems with halitosis are intraoral, proper OHI, support, and product recommendations will help in most of the cases.

However, if you find yourself faced with a patient that has stellar home care, yet still suffers from halitosis, it may be time to explore other etiologies. A review of other systemic symptoms may lead to a better understanding of other possible factors. A referral to their primary care physician may be the next step to help patients not only manage their halitosis but possibly their overall health.

The next time you find yourself struggling to manage a patient concerned with halitosis, try to think outside the box. These are just a few of the extraoral conditions that may be contributing to halitosis. The oral-systemic link is strong and should be discussed when all dental interventions have been unsuccessful.

Before you leave, check out the Today’s RDH self-study CE courses. All courses are peer-reviewed and non-sponsored to focus solely on pure education. Click here now.

Listen to the Today’s RDH Dental Hygiene Podcast Below:


  1. Kapoor, U., Sharma, G., Juneja, M., Nagpal, A. Halitosis: Current concepts on etiology, diagnosis, and management. Eur J Dent. 2016; 10(2): 292–300. DOI:10.4103/1305-7456.178294. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4813452/
  2. Falcão, D.P., Vieira, C.N., Batista de Amorim, R.F. Breaking paradigms: a new definition for halitosis in the context of pseudo-halitosis and halitophobia. J Breath Res. 2012; 6(1): 017105. DOI:10.1088/1752-7155/6/1/017105. Retrieved from https://pubmed.ncbi.nlm.nih.gov/22368258-breaking-paradigms-a-new-definition-for-halitosis-in-the-context-of-pseudo-halitosis-and-halitophobia/
  3. Mahmudul Hasan, S.M. Female are More Prone to Halitosis Due to the Changing of the Hormonal Balance-A Cross Sectional Study in Bangladesh. Am J Biomed Sci & Res. 2019; 3(2): AJBSR.MS.ID.000643. DOI: 10.34297/AJBSR.2019.03.000643. Retrieved from https://biomedgrid.com/fulltext/volume3/female-are-more-prone-to-halitosis-due-to-the-changing-of-the-hormonal-balance-a-cross-sectional-study.000643.php
  4. Trimethylaminuria. U.S. National Library of Medicine. Genetics Home Reference. Retrieved from https://ghr.nlm.nih.gov/condition/trimethylaminuria#diagnosis
  5. Phillips, I.R., Shephard, E.A. Primary Trimethylaminuria. 2007 Oct 8 [Updated 2015 Oct 1]. In: Adam MP, Ardinger HH, Pagon R.A., et al., editors. GeneReviews® [Internet]. Seattle (W.A.): University of Washington, Seattle; 1993-2020. Retrieved from: https://www.ncbi.nlm.nih.gov/books/NBK1103/
  6. Hypermethioninemia. U.S. National Library of Medicine. Genetics Home Reference. Retrieved from https://ghr.nlm.nih.gov/condition/hypermethioninemia#diagnosis
  7. Agranulocytosis. Cleveland Clinic. Retrieved from https://my.clevelandclinic.org/health/diseases/15262-agranulocytosis
  8. Ghom, A.G. Textbook of Oral Medicine. Retrieved from https://books.google.com/books?id=vxVPBQAAQBAJ&pg=PA1005&lpg=PA1005&dq=agranulocytosis+and+bad+breath&source=bl&ots=Zc10e8QUu5&sig=ACfU3U2WZkVc48ZQooVOmvoIHP5Ht6yyfg&hl=en&sa=X&ved=2ahUKEwiarp6W1JLnAhURY6wKHTLeA1EQ6AEwGXoECAwQAQ#v=onepage&q=agranulocytosis%20and%20bad%20breath&f=false
  9. Inaba, M., Inaba, Y. Human Body Odor: Etiology, Treatment, and Related Factors. Retrieved from https://books.google.com/books?id=mg1JCAAAQBAJ&pg=PA102&lpg=PA102&dq=agranulocytosis+and+bad+breath&source=bl&ots=gTSYroEpo9&sig=ACfU3U2PGA34Wed7Ku2iiOu5lkW3xSygKw&hl=en&sa=X&ved=2ahUKEwiarp6W1JLnAhURY6wKHTLeA1EQ6AEwGnoECA0QAQ#v=onepage&q=agranulocytosis%20and%20bad%20breath&f=false
  10. Bronchiectasis. National Heart, Lung, and Blood Institute. Retrieved from https://www.nhlbi.nih.gov/health-topics/bronchiectasis