The causes of halitosis can be numerous and may even intensify one another. That is why many healthcare professionals suggest addressing each cause in turn, while neutralizing the effect - oral odor - as well.
A 2006 review of the agents of bad breath, which was published in the British Medical Journal (BMJ), lists dozens of origins for the odor it leaves on the body's exhalations. It states that halitosis is common in individuals of all ages and that poor dental hygiene is the most common cause.
Conditions like gingivitis, periodontitis, tooth decay, plaque buildup and even a coated tongue can leave bad smells in the mouth. Of course, certain gastrointestinal conditions may also contribute to halitosis, but the article specifies that cleaning the teeth and tongue can reduce its severity.
Fox News medical contributor Isadore Rosenfeld has stated that cleaning the teeth and tongue and rinsing them both with an antimicrobial product can keep bad breath at bay.
Much of the smell of bad breath consists of "odiferous sulphides and amines," the BMJ review notes. These molecules are released by bacteria that feed on food in the mouth. Neutralizing them may involve little more than swishing with a specialty breath freshener.