Nasal odour may be due to sinus infections or foreign bodies.Halitosis is often stated to be a symptom of chronic rhinosinusitis, however gold standard breath analysis techniques have not been applied. Theoretically, there are several possible mechanisms of both objective and subjective halitosis that may be involved. Tonsils
There is disagreement as to the proportion of halitosis cases which are caused by conditions of the tonsils. Some claim that the tonsils are the most significant cause of halitosis after the mouth. According to one report, approximately 3% of halitosis cases were related to the tonsils. Conditions of the tonsils which may be associated with halitosis include chronic caseous tonsillitis (cheese-like material can be exuded from the tonsillar crypt orifi), tonsillolithiasis (tonsil stones), and less commonly peritonsillar abscess, actinomycosis, fungating malignancies, chondroid choristoma and inflammatory myofibroblastic tumor. Esophagus
The lower esophageal sphincter, which is the valve between the stomach and the esophagus, may not close properly due to a hiatal hernia or GERD, allowing acid to enter the esophagus and gases to escape to the mouth. A Zenkers diverticulum may also result in halitosis due to aging food retained in the esophagus. Stomach
The stomach is considered by most researchers as a very uncommon source of bad breath.
Contrary to the popular belief that Listerine coined the term halitosis, its origins date to before the products existence, being coined by physician Joseph William Howe in his 1874 book The Breath, and the Diseases Which Give It a Fetid Odor, although it only became commonly used in the 1920s when a marketing campaign promoted Listerine as a solution for "chronic halitosis". The company was the first to manufacture mouth washes in the United States. According to Freakonomics: Listerine "...was invented in the nineteenth century as powerful surgical antiseptic. It was later sold, in distilled form, as both a floor cleaner and a cure for gonorrhea. But it wasnt a runaway success until the 1920s, when it was pitched as a solution for "chronic halitosis"— a then obscure medical term for bad breath. Listerines new ads featured forlorn young women and men, eager for marriage but turned off by their mates rotten breath. "Can I be happy with him in spite of that?" one maiden asked herself. Until that time, bad breath was not conventionally considered such a catastrophe, but Listerine changed that. As the advertising scholar James B. Twitchell writes, "Listerine did not make mouthwash as much as it made halitosis." In just seven years, the companys revenues rose from $115,000 to more than $8 million." Alternative medicine
According to traditional Ayurvedic medicine, chewing areca nut and betel leaf is a remedy for bad breath.