Bad Breath: Symptoms, Causes, and Treatment

Table of Contents

What Causes Bad Breath Even After Brushing?

Severe mouth odor is typically caused by dental infections that require treatment by a qualified dental professional. Other common causes of bad breath include diets containing certain foods, smoking and other tobacco use, poor oral hygiene, some medications, and may even result from health conditions present throughout the body.

Sadly, the term bad breath does not need much explanation. You inherently know what we mean because you have probably experienced it either for yourself or through a loved one. We understand the adjective bad to mean that the odor of bad breath is unpleasant or offensive. While we can certainly smell someone’s mouth odor when they breathe, we also detect it during speaking and laughing.

The sense of smell has strong associations with our memory. This applies to both pleasant and unpleasant smells. For example, at the mention of bad breath, you can probably easily call to mind a time when you noticed that a friend or colleague had particularly bad breath. We are all rightly sensitive about the state of our own breath. We hope that after reading this article, you feel more informed and prepared to tackle bad breath.

Are Masks Making You More Aware of Your Bad Breath?

One of the strangest phenomena associated with bad breath is our inability to smell it when it is coming from our own mouths. Most people are completely unaware that their breath smells less than fresh. We can’t trust the fact that we don’t smell anything from our own mouths. We have to ask others to get a true assessment.

Interestingly, we find that more people are noticing an unpleasant smell as they wear the requisite masks during the current COVID-19 pandemic. So it is appropriate to ask the question: Does wearing a mask give us the opportunity to smell our own breath?

While there is not scientific evidence to support an answer to the question, we believe the answer is yes. It makes sense to assume that the masks trap our exhaled air against the face, providing the opportunity to smell it. If that exhaled air contains the sulfurous gases of bad breath, we believe that our noses are more likely to detect them in that trapped environment.

If you are noticing a bad smell underneath your own mask, do not worry! First of all, you’re not alone. One out of every four people experiences bad breath. Secondly, you are not stuck with your bad breath; in most cases, we can help you fix it.

Why Bad Breath Is Bad

As dentists, we are your best resource for addressing the problem of bad breath. We are in the perfect position to recognize, discuss, and treat this particular problem. Bad breath is complex in that it has both emotional and physical repercussions. We hear the distressing emotional consequences of bad breath in our confidential conversations with patients, and we see the negative health implications inherent in severe bad breath.

Emotional Implications

When someone struggles with chronic bad breath, it causes emotional distress. When you are aware that you have bad breath, you are likely to struggle with confidence and avoid close conversations, exuberant laughter, and intimate encounters. People with self-consciousness regarding bad breath shy away from social interactions to spare themselves embarrassment.

Unfortunately, even more people are unaware of strong bad breath. These may suffer rifts in personal relationships, avoidance by people at work or social occasions, or romantic rebuffs without understanding the underlying cause. People with chronic bad breath are less likely to advance within the workplace.

Health Implications

Even more concerning to us, as dentists, are the potential health implications of chronic bad breath. Persistent bad breath that does not respond to home care may be the result of a serious health problem. Your bad breath could be a warning sign that you have a dental infection or other medical condition.

Because more than ninety percent of bad breath originates in the mouth, your dentist is your first line of defense. In many cases, bad breath is simply a symptom of a bigger problem. Seeing your dentist first is important to rule out dangerous dental infections as the cause of the unpleasant odor.

We also work closely with medical professionals to help you find a solution when the source of the bad odor is not in the mouth.

What Are the Causes of Bad Breath?

Understanding the causes of bad breath can help you make the necessary decisions and changes to address the problem. There are quite a few potential causes of bad breath, and many people have more than just one. While it can be tough to discern exactly which of these problems are leading to the unpleasant smell, we have tools to address each one of them.


This one is, obviously, the simplest to understand and to address. For example, raw onions give you bad breath. Don’t eat raw onions. At least, you have the option to choose when to eat foods that have a particularly strong smell that lingers for a while after eating.

The bad breath caused by certain foods is easily remedied by altering the diet. You can maintain a perfectly healthy diet while avoiding particularly smelly foods. Some studies even show that diets high in dairy products can cause bad odors in the mouth. If you are unsure which food is responsible for your bad breath, these are the top ones to avoid:

  • Onions
  • Garlic
  • Tuna fish
  • Fermented vegetables
  • Large amounts of dairy products


Certain habits can also cause bad smells in the mouth. In general, these habits include smoking of any kind, smokeless tobacco use and e-cigs/vaping. Smoking cigarettes causes the strongest, most noticeable alteration in your breath. Smoker’s breath has a very distinct odor that does not respond well to home treatments.

The only way to prevent the bad breath caused by these habits is to quit the habit. We don’t like telling people what to do, but considering all of the serious health consequences of smoking, tobacco and vaping, we feel comfortable telling you to just quit. Not only will it improve your breath, it will protect your overall health.

Poor Oral Hygiene

“Poor oral hygiene” is our way of saying that someone does not properly clean his or her teeth on a consistent basis. The purpose of oral hygiene (which includes brushing, flossing, and can include using mouthwash) is to remove plaque from the teeth. Dental plaque is the “home” for the bacteria that cause bad breath. These bacteria create a by-product of stinky gases called Volatile Sulfur Compounds or VSCs.

When you clean away plaque, you get rid of these bacteria. When you get rid of these bacteria, you stop the production of smelly gases that make up bad breath. The problem is that many people do not clean away plaque adequately and/or consistently.

Many people do brush and floss consistently, but their techniques are incorrect. This means that even though they are going through the motions, they are leaving plaque on the teeth. Others do not maintain a consistent routine of brushing and flossing every single day. Obviously, this also allows plaque to remain on the teeth.

In addition to plaque on the teeth, it can also accumulate in the deep grooves and pits on the tongue. For this reason, many people also need to add tongue cleaning to their oral hygiene routines.

Dental Problems

The most common cause of chronic severe bad breath is a dental infection. We do not mean a simple overgrowth of oral bacteria due to a buildup of plaque. That is what we discussed in the previous section. We mean an active dental disease, like decay (cavities) or gum disease.

Both cavities and gum disease are bacterial infections of the oral tissues. Tooth decay is a bacterial infection of the hard tissues of a tooth, and gum disease is an infection of the hard and soft tissues surrounding a tooth (also called periodontal disease). Both of these conditions consist of the reproduction and proliferation of specific disease-causing bacteria, and they stink.

Large cavities and progressive gum disease both provide perfect hiding spots for large collections of bacteria. As cavities worsen, bacteria accumulate in actual holes in the teeth. When gum disease progresses, deep pockets develop between the tooth’s roots and the surrounding gum and jawbone. The deep pockets are breeding grounds for bacteria that become more dangerous as the pocket deepens.


Millions of Americans take multiple prescription medications every day, and the combinations of medications can cause severe dry mouth. A dry mouth does not smell good. In a dry mouth, bacteria can proliferate more readily, leading to heavier plaque buildup and a higher risk for dental diseases.

Saliva is the body’s natural defense against disease-causing bacteria in the mouth. When medications inhibit the production of saliva, your mouth suffers, and so does your breath.

Health Conditions

There are a few health conditions outside the mouth that can contribute to bad breath. Because dental problems are far more likely to be the culprit, we always rule them out first. If your dentist rules out any dental problems as the source of your bad breath, you then likely need to look outside the mouth.

Chronic sinus infections and post-nasal drop often lead to bad breath, as do persistent throat infections. Some people suffer from infections in the stomach that travel up the esophagus into the mouth, leaving a bad smell. Severe acid reflux and GERD can cause a bad odor, and certain metabolic disorders emit unpleasant gases through the breath.

If we believe that your bad breath originates elsewhere in the body, we will work with your primary care physician to help you find the right solution for fresh breath.

Treatment for Bad Breath

As we mentioned earlier, you do not have to live with bad breath. There are various approaches to the treatment of bad breath, and the good news is that you can begin at home!


Many people with chronic bad breath actually have a combination of causes. You can start improving your breath immediately by addressing the daily contributors to unpleasant odors in the mouth. Follow these steps for drastically improving your breath at home!

1. Dietary Changes – When you identify the particular foods in your diet that create a bad smell, you can avoid them. Ask your loved ones to help you monitor times when your breath is worse than others. It may take some tracking to find which foods have the strongest effect. As you adjust your diet, you should experience an almost immediate improvement in your breath.

2. Brush Up on Your Oral Hygiene – (Pun intended) You are the only one who can remove dental plaque on a daily basis. This takes both commitment and a great technique. Don’t’ rush through your oral hygiene routine. Ask your dentist or dental hygienist for tips on the best ways to brush and floss. Consider adding a flexible tongue cleaner to your routine to remove plaque from the tongue. As you consistently remove plaque, you reduce the bacterial count in your mouth, which lowers the risk for bad breath.

3. Quit Your Bad Habits – We can’t stress enough the importance of stopping the use of tobacco products and all forms of smoking. The risks to your overall health are too high. Finally achieving fresh breath is just an added bonus.

4. Hydrate! – Many people suffer from dry mouth, which aggravates bad breath. Whether the dry mouth is the result of a prescription medication side effect or simple dehydration, one important solution is drinking lots of water. Drinking water provides the necessary resources to your salivary glands for the production of saliva. It also helps to flush away dental plaque and food debris.

5. Use a Mouthwash – Many mouthwashes on the market today target bad breath with ingredients like cetyl pyridinium chloride, activated chlorine dioxide, and zinc. The important thing to understand about mouthwash is that you must avoid those containing alcohol. It does not kill bacteria in the mouth, and actually worsens the situation by drying out the mouth.

Professional Care

When you do not notice a drastic improvement in your breath after taking the above self-care steps, you need to seek professional help. Professional care for bad breath will include the following steps.

1. Oral Hygiene Education – Because plaque accumulation is a major contributor to bad breath, our dentists and dental hygienists will assess your current effectiveness in removing plaque. There may be areas you are missing, and we can recommend different strategies to help you successfully clean your teeth at home between your professional teeth cleanings.

2. Dental Treatment of Active Diseases – You cannot win the fight against bad breath if you have cavities and/or gum disease. Both of these bacterial infections continue to worsen and grow over time without intervention. Stop them by undergoing any recommended dental treatment.

3. Rule Out any Other Oral Origin of Bad Breath – We often find tricky spots of plaque buildup on the tongue or tonsil region. We can quickly recognize a dry mouth and help you treat it. You may have an area of consistent food collection that we can address.

4. Refer You to Your Medical Doctor – When all oral causes of bad breath have been ruled out or repaired, we will work with your medical doctor to help you solve persistent bad breath. Some patients will need to see an ear, nose and throat specialist (ENT) to address chronic sinus or throat infections. Others need help from a gastroenterologist (GI specialist) for issues in the stomach and/or esophagus.

Bad Breath: Your Next Steps

Bad breath is not a condition you have to endure. We understand both the emotional and physical effects of chronic bad breath, and we are here to help. We provide this type of valuable information so that you can begin to address the problem of bad breath on your own. We are also available to provide the professional care you may need when self-care does not produce the results you need.