Halitosis - Symptoms, diagnosis and treatment | BMJ Best Practice US

2026-04-20

Halitosis - Symptoms, diagnosis and treatment | BMJ Best Practice US

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Halitosis describes any disagreeable odor of expired air from the mouth. In most cases, it arises from the presence of volatile sulfur compounds (VSCs), diamines, and short-chain fatty acids in the exhaled air.

It is more likely to occur in individuals with oral, dental, and nasopharyngeal disease that can increase the accumulation of food debris and bacterial plaque.

If persistent and severe, it is defined as “pathologic halitosis.” Very rarely, a spectrum of systemic disorders may also give rise to altered breath smell.

The diagnostic approach is largely based on patient history and clinical examination (including smelling the exhaled air of the mouth and nose). More objective diagnostic tools, which may be used in a specialist setting, include oral breath sulfide monitors and gas chromatography devices, and detection of oral bacteria likely to give rise to halitosis.

When associated with dental, oral, and nasopharyngeal disease, appropriate management of these conditions usually results in reduced accumulation of bacteria and reduced malodor. Therapy of halitosis due to systemic disease is based on treatment of relevant associated disorder.

Some individuals complain of oral malodor yet have no detectable halitosis Such pseudohalitosis remains difficult to resolve. Affected individuals require appropriate psychological investigation and treatment.

BMJ Best Practice topics are updated on a rolling basis in line with developments in evidence and guidance. The peer reviewers listed here have reviewed the content at least once during the history of the topic.

Peer reviewer affiliations and disclosures pertain to the time of the review.

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