Contributing / Risk factors for bad breath.

- How Smoking, Dry Mouth (morning breath, xerostomia), Gum Disease, Sinus Conditions, Foods, Medical and Dental Conditions can help to cause halitosis.


Link to gum disease section.


Link to sinus conditions section.

This page outlines a number of factors that can make it more likely that you'll have problems with halitosis. They include:


As you read through the explanations of these issues, take notice of how many of them directly relate to:

  1. Conditions that promote the growth of oral bacteria.
  2. Situations that make it more difficult clean those areas where oral bacteria reside.

These issues are important because they're the actual reasons why you have bad breath. The co-factors discussed on this page just help to set the stage for them.

(Don't overlook our other pages that provide in-depth information about: 1) The underlying cause of breath malodor. and 2) How to effectively clean the areas where bad breath originates.)

Risk and contributing factors -

A) Smoking.

You're probably familiar with the odor of people who have "smoker's breath." Much of this smell is caused by tar, nicotine, and other stinky compounds found in tobacco smoke that accumulate on a person's teeth and oral soft tissues (tongue, cheeks, gums,...).

A 'No Smoking' sign.

Smoking can aggravate breath problems.

Short of quitting smoking, there's no way to eliminate smoker's breath, although practicing immaculate oral hygiene can help to minimize it.

How smoking compounds a person's breath problems.

Smoking creates other risk factors. For example, tends to dry out oral tissues.

A decrease in oral moisture diminishes the beneficial washing, diluting and buffering effect of saliva on oral bacteria and the waste products they create. This topic is discussed in greater detail below.

It's also known that people who smoke are at greater risk for having problems with periodontal disease (gum disease). We discuss the role this condition plays in causing bad breath below too.

B) Dry mouth.

Morning breath.

Everyone, even including people who don't really have much of an odor problem, probably notice that their breath is least pleasant in the morning, when they first wake up. The words "sour" and "stale" are often used to describe what's noticed.

This happens because during the night a person's mouth tends to dry out, due to the body's natural tendency to lower the flow of saliva as we sleep. And if you snore or sleep with your mouth open, this drying effect, and thus your morning breath, can be even more noticeable.

In most cases morning breath can be expected to disappear after a person has performed their morning oral hygiene and has had a chance to rehydrate their mouth.

Similar conditions.
  • This same type of drying/souring event is often noticed by teachers, lawyers, or anyone else who must speak for extended periods of time.
  • People who breathe through their mouth, or are fasting or else are under stress (conditions that can reduce salivary flow), may find they have a chronically dry mouth and thus persistent problems with breath odors.

Why oral moisture is so important.

An explanation for this phenomenon lies in the fact that the moisture in our mouth helps to keep it clean.

  • The presence of oral fluids encourages us to swallow. And with each swallow we take we expel bacteria from our mouth, as well as the food and debris on which they feed.
  • Oral moisture dilutes and washes away the smelly waste products that oral bacteria produce.
  • Saliva is the body's natural mouth rinse. It contains compounds that kill bacteria and buffer their stinky waste products.

So, when our mouth dries out, each of these mechanisms is inhibited. The net result is one where the conditions for bacterial growth are enhanced, while the neutralization of odoriferous bacterial waste products is diminished.

C) Xerostomia.

Some people have a chronically dry mouth. This condition is termed "xerostomia." A study by Quirynen (2009) [page references] determined that this problem was the underlying cause of about 3% of halitosis cases.

Medications - Having xerostomia can be a side effect of taking certain types of medications. Antihistamines (allergy and cold medications), antidepressants, blood pressure agents, diuretics, narcotics, or anti-anxiety medications may all be contributing factors for this condition.

Age - A person's age can also be at issue. For most people, as they get older, chronic mouth dryness becomes more and more of a problem. That's because their salivary glands tend to work less effectively and the composition of the saliva they produce changes too.

Gum disease as a complicating factor.

People who have xerostomia are at greater risk for developing gum disease and the breath issues that come with it (see our next section). A part of this risk is to to the comparatively dried out nature of the person's dental plaque, making it more difficult to remove.


D) Periodontal (Gum) disease.

Gingivitis and periodontitis (two forms of gum disease) are frequently the underlying cause of a person's breath odor.

Ask any dentist, the smell coming from the mouth of a person with active periodontal disease (an advanced form of gum disease) can be so distinctive that a dentist can correctly diagnose their condition even before they begin their examination.

Collectively these conditions (or more specifically the bacteria that cause them) are considered to be the second leading cause of halitosis. Quirynen (2009) determined that around 15% of cases were due to gum disease alone, and an additional 24% of cases caused by it and bacterial coating on the person's tongue.

Who's at greatest risk for odors associated with gum disease?

  • Gingivitis (inflammation of the gum tissue) is common in all age groups when proper oral home care (brushing and flossing) is not practiced.
  • Periodontitis (inflammation of both the gum and bone tissue that surrounds the teeth) is typically more of a problem for "older" people (such as those over the age of 35 and beyond).

That means, the older we get, the more likely it is that our breath issues are related to the health of our gums.

How gum disease affects your breath.

  • It's both the waste products of the microorganisms that cause gingivitis and periodontitis, and the by-products associated with the inflammation that they create, that produce the volatile sulfur compounds that causes breath malodor.

Healthy vs. diseased gums.

Animation showing periodontal pockets that can harbor bacteria and cause bad breath.

Periodontal disease can result in pocketing around teeth.

Additional factors with periodontitis.
  • Advanced forms of periodontitis typically result in serious damage to the bone that holds teeth in place.

    As it occurs, deep spaces form between the teeth and gums (termed "periodontal pockets," see illustration). They provide the ideal anaerobic living environment for the types of bacteria that cause bad breath.

  • Research has found that the amount (as measured by weight) of odor-causing coating that's present on the tongue of people who have periodontitis is greater than those who don't.

    Studies have also determined that the level of volatile sulfur compounds coming from this film is four times greater for people that have periodontal disease than control groups.

    (Suzuki 2012, Sanz 2001)

The above information suggests that in the case of breath odor associated with gum disease, the cure lies in both resolving the periodontal issue and instituting a regimen of effective tongue cleaning.

E) Sinus conditions.

Sinus conditions can cause breath problems.

Illustration showing the source of post-nasal drip.

Discharge from the sinuses into the mouth can aggravate breath problems.

1) Postnasal drip.

Upper respiratory infections and allergies can create a postnasal drip that falls onto the back portion of a person's tongue. (Via the opening behind the soft palate. See graphic.)

This discharge often has a foul taste and smell. What's worse, the bacteria that cause bad breath can use it as a food supply.

2) Dry mouth.

As a compounding factor, people who have a sinus condition will often have a stuffed up nose and will need to breathe through their mouth.

This drying effect can create an environment that promotes bad breath. Additionally, sinus sufferers are likely to take antihistamines, a type of medicine that's known to cause mouth dryness (see above).

Other upper respiratory infections.

Tonsillitis (an infection of the fleshy pieces of tissue on each side of your throat) or pharyngitis (infection of the throat itself) can be the source of breath odor. As a tip-off that this is the case, you may also notice a sore throat, difficulty with swallowing or enlargement of the lymph nodes in your neck or under your jaw.

FYI: A study by Quirynen (2009) determined that roughly 4% halitosis cases originated from non-oral sources such as problems associated with the nose, throat, gastro-intestinal or respiratory tract infections or systemic diseases.

F) Medical conditions.

Some medical issues are known to be associated with the presence of mouth odors. If a person's bad breath persists after they have consulted with their dentist and tried the usual simple solutions, then a consultation with their medical doctor may be indicated.

Your doctor will of course know what types of conditions to look for. But, in general, they will evaluate you for problems associated with your respiratory (pulmonary or bronchial), hepatic (liver), renal (kidney), endocrine (glands that produce hormones) and gastrointestinal (stomach and intestine) systems.

Non-oral causes.

Medical conditions and medications are categorized as "non oral" causes of bad breath. And while these factors can be an aggravating or even the fundamental cause, in the majority of cases the origin of a person's breath problems is in their mouth and a solution should be first looked for there. Research suggests that roughly 85 to 90% of all cases of halitosis have an oral origin. (Danser 2003)

G) Foods.

Everyone knows that certain foods and beverages have a reputation for causing bad breath. Some of the most notorious ones are garlic, onions, alcohol and spicy foods in general.

How foods can cause bad breath.

  • When we eat, our digestive system breaks down the food we have consumed into its component molecules. Some of them have a very unpleasant odor.
  • As these molecules are created, they are absorbed into our blood stream so they can be distributed throughout our body as nourishment.
  • As our blood travels through our lungs, some of these molecules are released into them. As a result, as we exhale, they get expelled with our breath too.
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"Non oral" bad breath.

While experiencing this type of condition can be annoying and embarrassing, it's not the main concern of the pages of our topic. It's often referred to as "temporary" or "transient" halitosis. Additionally, it's classified as a type of non-oral malodor, meaning the source of the person's breath problems don't originate in their mouth.


This condition will resolve on its own, typically within 48 hours, as your body completes the process of breaking down and utilizing, or else excreting, the offending compounds. You can control this type of malodor simply by avoiding or minimizing your consumption of certain types of foods.

Illustration of an X-ray of a decayed tooth with an abscess.

Bacteria associated with infected teeth can be the source of breath odors.

H) Dental conditions.

Untreated dental conditions can be the cause of or contribute to a person's breath problems.

  • Active infections, such as those associated within abscessed teeth, partially erupted wisdom teeth (pericoronitis) or dental implants (periimplantitis), can be at fault.
  • Teeth that have large voids (due to decay or fracture) can trap enough debris and bacteria that they become the source of foul odors.

I) Dentures.

Dentures (complete dentures, full dentures, partial dentures, etc...) can have a big influence on the quality of a person's breath.

How to test for denture breath.

Try this test to see if your dentures might be the source of your breath problems.

  • Remove your dentures and place them in a baggie.
  • Seal the baggie shut and let it sit for about four or five minutes.
  • Now, crack the baggie open and take a whiff.

For better or worse, that's what your breath smells like to others. Use this link for more information bout the causes of denture breath and how to treat it.

Now you know the reasons why you have bad breath. Our next page explains how to cure it.



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