Last revised by Daniel J Bell on 23 Aug 2022

Halitosis, also known as fetor oris, refers to the symptom of foul oral odor, commonly termed "bad breath". This is most commonly due to poor dental hygiene.



It is thought to be caused by the presence of volatile sulfur compounds that are produced by bacteria. The underlying cause is most commonly poor dental hygiene, however a range of non-dental etiologies are less commonly responsible, including respiratory tract infection, liver failure, and renal disease, as well as the presence of a pharyngeal pouch.

A rare form of fetor oris is fecal oris, the odor of feces on the breath, most commonly seen with a gastrocolic fistula 2.

Practical points

Halitosis does not require imaging on its own but imaging may be undertaken if there are other symptoms which raise the suspicion of an underlying cause other than bacterial overgrowth. This is usually in the form of a barium swallow or other fluoroscopic investigation.

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