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Post-nasal drip most definitely causes bad breath

By – Bad Breath Expert
Posted: June 5, 2012, Updated: March 29, 2016
SUMMARY: The causes of bad breath can be pretty complex and confusing for folks not in the field of oral health.

post nasal drip drops

To attack bad breath, it is essential that we know what causes it. Now, you might not think that that's a very difficult task, but in fact the field of breath research is constantly changing as experts examine and re-evaluate the most common causes of halitosis. One of these in particular - post-nasal drip - is an especially slippery topic.

Quite literally...

This drip occurs when the nasal passages get irritated, usually by pollen, allergens, dust or smoke. Minor colds or sinus infections can also lead to this problem. No matter what causes it, the results of post-nasal drip are twofold: It almost invariably leads to bad breath and a chronic cough.

Both of these problems stem from the thin, watery mucus that runs down the back of the nasal passages and into the throat. Of course, it's not always easy to identify post-nasal drip as the problem, since so many other factors can contribute to bad breath. Even some dental experts disagree as to whether the drip can cause odor.

For example, in a Q-and-A recently published by the Chicago Tribune, an otorhinolaryngologist associated with the Mayo Clinic stated pretty unequivocally that "post-nasal drip usually isn't related to bad breath." The article explains that the drip does not cause a breath stench in the way that, say, mucus from a stuffy nose or infected sinus would.

This is because, as the author points out, the thin mucus associated with post-nasal drip is inherently odorless.

That may be true, but an odorless substance can certainly contribute to smelly breath if it gives oral bacteria something to eat.

All signs point to yes (post-nasal drip does cause odor)

At TheraBreath, our clinical research has proven that post-nasal drip increases the intensity of halitosis. Mucus is a rich source of food for bad breath-related bacteria that reside at the back of the throat. These microbes convert this food source into pungent waste, which is the source of the resultant oral odor.

Hence, while post-nasal drip may be odorless in and of itself, it still contributes to oral odor in a predictable (and preventable) way.

Even the Mayo Clinic agrees. Regardless of the Tribune piece, here is what appears on the Clinic's official website, under the causes of halitosis:

"Mouth, nose and throat conditions. Another source of bad breath is the nasal passages. For example, bad breath is associated with sinus infections because nasal discharge that drips from your sinuses into the back of your throat (post-nasal drip) can cause mouth odor."

This information isn't outdated, either. Judging from the date stamp at the bottom of the page, it was last reviewed and updated just two years ago.

So if it's real and preventable, how can you treat post-nasal drip?

There are several simple, inexpensive and "healthier" remedies for post-nasal drip and the odor it causes. The first is a specialty breath freshening nasal spray, one designed to neutralize odors and cleanse away irritants. Such products are especially nice because they accomplish two things at once, giving you relief from the drip and easing your halitosis.

To banish drip-related odor double-quick, consider gargling with a specialty breath freshening rinse or, alternatively, a mixture of warm water and a little salt. This can cleanse away mucus, soothe your throat and even potentially dislodge any tonsil stones that may be lurking at the back of your mouth. Dr. Harold Katz, America’s bad breath expert,  has developed easy to use TheraBreath Nasal Drops by blending oxygenating compounds and natural antimicrobials (without any zinc). Squeezing 1-2 drops into each nostril twice daily stops the interaction between the anaerobic bacteria and the mucus, thereby eliminating any odor production. They can be found  exclusively at

And of course, taking over-the-counter allergy medications and avoiding smoking both help prevent post-nasal drip from occurring in the first place.

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