What causes halitosis?

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Last updated: February 10, 2025View editorial policy

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From the Guidelines

Halitosis is primarily caused by poor oral hygiene habits and gingival and dental health status.

Key Factors

  • Oral health factors: including oral hygiene habits, gingival and dental health status, implants, intra-oral appliances or dentures 1
  • Lifestyle factors: such as smoking and high sugar intake frequency also contribute to the development of halitosis 1

Underlying Causes

The underlying causes of halitosis can be attributed to the accumulation of bacteria in the mouth, which can be exacerbated by poor oral hygiene habits and certain lifestyle factors. Regular dental check-ups and good oral hygiene practices, such as brushing and flossing, can help prevent the development of halitosis.

From the Research

Causes of Halitosis

  • Halitosis is a multifactorial condition with various underlying causes, including oral and systemic diseases 2
  • Local factors, such as poor oral health care, deep carious lesions, periodontal disease, and tongue coating, play an important role in the majority of cases 3, 4
  • Extraoral factors, such as ear-nose-throat conditions, gastrointestinal, respiratory, and systemic diseases, may also contribute to oral malodor 3, 5, 6
  • Unhealthy eating habits and an imbalance of microorganisms in the oral cavity and gastrointestinal tract are primary causes of halitosis 2
  • Dental caries, periodontal disease, xerostomia, and digestive disorders like gastritis and irritable bowel syndrome are also related to the development of halitosis 2

Oral Causes of Halitosis

  • Poor oral hygiene 4, 5, 6
  • Deep carious lesions 4
  • Periodontal disease 4, 5, 6
  • Tongue coating 4, 6
  • Impacted food or debris 4
  • Mucosal ulcerations 4
  • Peri-implant disease 4
  • Pericoronitis 4

Systemic Causes of Halitosis

  • Gastrointestinal diseases 3, 2, 5, 6
  • Respiratory diseases 3, 5, 6
  • Systemic diseases, such as hepatic, pancreatic, and nephritic insufficiencies 6
  • Trimethylaminuria 6
  • Medication 6

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Halitosis: etiology, prevention, and the role of microbiota.

Clinical oral investigations, 2023

Research

Halitosis: a review.

SADJ : journal of the South African Dental Association = tydskrif van die Suid-Afrikaanse Tandheelkundige Vereniging, 2005

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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