Bad breath, also called halitosis, can be embarrassing and in some cases may even cause anxiety. There are a number of potential causes of halitosis but the vast majority comes down to oral hygiene. Often the bad odor caused by bacteria present below the gum line and on the back of the tongue. However, some halitosis is caused by other conditions, including disorders in the nasal cavity, sinuses, throat, lungs, esophagus, stomach or elsewhere.
When the cause is a disorder of the nose and sinuses, the air exiting the nostrils has a pungent odor that differs from the oral odor. Nasal odor may be due to sinus infections or foreign bodies.
Halitosis is often stated to be a symptom of chronic rhinosinusitis. Conditions of the tonsils which may be associated with halitosis include chronic caseous tonsillitis (cheese-like material can be exuded from the tonsillar crypts), tonsillolithiasis (small, bacteria covered "stones" which form on the tonsils at the back of the throat and produce odor), and less commonly peritonsillar abscess, actinomycosis (sulfur producing infectious organisms) and some cancers of the mouth and throat.
The oldest way for unpleasant odor detection is by smelling with the nose. Measurement of unpleasant odors by smelling the exhaled air of the mouth and nose is called organoleptic measurement. It is the simple way for the detection of halitosis.
There are a variety of sophisticated detectors that can rate odor more precisely including:
Halimeter: detects low levels of sulfur
Gas chromatography: measures three volatile sulfur compounds - hydrogen sulfide, methyl mercaptan and dimethyl sulfide
BANA test: measures for a specific enzyme produced by halitosis-causing bacteria
Beta-galactosidase test: levels of the enzyme beta-galactosidase have been found to correlate with mouth odor.
There is no single treatment for halitosis. The treatment will depend on what is causing the problem. Avoiding dehydration and good oral hygiene, including brushing and flossing, are important. Some nonalcohol based mouthwashes; lozenges and toothpastes can assist in fighting halitosis.
Gentle but effective tongue cleaning may also be required. A variety of tongue brushes and scrapers have been produced in recent years. The tongue should be brushed in a gentle but thorough manner, from the back towards the front of the tongue, keeping in mind that the hardest to reach back portion smells the worst.
People with chronic sinusitis may find the regular use of a saline nasal spray or rinsing helpful. After evaluation with a physician, a course of an antibiotic may also help.