What causes bad breath (halitosis)?

Nobody wants bad breath. Listen as Dr. Maria Lopez Howell explains the causes of bad breath and how to treat it.
Todd A. Welch, DMD
There are millions of people throughout the world currently struggling with bad breath complications, and most probably this is why there is such a wide array of breath freshening products available.

In case you are struggling with bad breath, although you have tried all the existent freshening products without good results, you must establish the cause of this condition. If you are able to find the root of bad breath problem, you will also be able to find the best treatment solution.

One of the very first causes of bad breath is bad oral hygiene. Everybody knows that regular brushing, flossing and tongue cleansing greatly helps in reducing bad odor.

Xerostomia, or the “dry mouth” syndrome might be yet another cause. When your mouth feels dry, it means that you are not producing enough saliva. This condition might be caused by certain medication intake or processes such as chemotherapy, radiotherapy and of course dehydration.

In order to make bad breath go way, you need to treat the dry mouth condition first. Make sure to drink plenty of water in order to stay hydrated, and in order to stimulate saliva production you can also chew regularly sugar-free gum.

Certain oral infections and periodontal disease can also be a major cause of bad breath. Plaque accumulates extremely quickly on the teeth, and the food particles and certain bacteria can make your breath smell quite unpleasant.

If no measure is quickly taken, the bacteria can slowly destroy all that soft tissue surrounding your teeth. From there on, you are automatically exposed to tooth decay and gum disease infections, which cause the bad breath. It is extremely important to visit regularly your dentist, and let him know about your bad breath problem; there is professional treatment available, so you will soon get rid of this bad condition.

Then, there are certain other medical underlying conditions that bring about bad breath. If you are struggling with this condition, and you know that you have healthy teeth and gums, you might want to check with your doctor for some detailed medical investigations. Some diseases that usually cause bad breath include diabetes complications, bronchitis, acid reflux which is chronic, lung infections and liver complications.
Have you ever sat in church or someplace closed and smell something unpleasant from the person setting next to you? I think we all have. I use to amaze my wife with my keen sense of smell. More times than not the person has gum disease.

If you ever want to know what your breath smells like, floss your teeth and smell the floss. Gum disease or periodontal disease is caused by the accumulation of plaque through improper oral care or lack of flossing. This is exacerbated in the morning in the form of 'morning breath' with a dryer oral condition.

Even though periodontal disease is the most common etiology, it is not the only cause. There are many other causes which are medical or diet in nature. 

Halitosis can be linked to diet in nature. The popular low carbohydrate diet burns fat and produces a fruity acetone odor called 'ketone breath'. Other causes of halitosis from diet can be caused from onions, garlic, curry (the Indian spice which has been also linked with oral cancer), some cheeses, and some acidic beverages such as coffee.
Smoking and other tobacco products, such as chewing tobacco and snuff can cause bad breath. The dry mouth or xerosomia associated with smoking can cause periodontal disease not to mention the heat caused by taking a drag from a cigarrete, pipe, or cigar. Also associated with chewing tobacco and snuff is the irritation to the gum and there is an oral hygiene problem associated with the tobacco setting next to the periodontal tissues.

Next there are some four hundred medications that cause xerostomia which can cause periodontal disease and decay. If your dentist sees problems with this, there are ways to treat this.

There are also some medical conditions which can cause 'halitosis'. These are lactose intolerance, G.E.R.D., diabetes, Sjogren's syndrome, sinus infection, throat infections (tonsillitis or pharyngitis), local infections in the respiratory tract, and liver or kidney disease. So you can see going to the dentist it can be a matter of your medical health as well.

Finally people that have appliances in their mouth can have 'halitosis'. This is seen with partials or dentures that the patient has had for as few as five years. Acrylic can absorb plaque.

Remember your health is ultimately your responsibility. Keep good health with regular checkups.
Sally J. Cram, DDS
Bad breath (halitosis) is an unpleasant condition that can be cause for embarrassment. If you don't brush and floss daily, particles of food remain in the mouth, collecting bacteria, which can cause bad breath. Food that collects between the teeth, on the tongue and around the gums can rot, leaving an unpleasant odor. Some people with bad breath aren’t even aware there’s a problem. If you’re concerned about bad breath, see your dentist. He or she can help identify the cause and, if it’s due to an oral condition, develop a treatment plan to help eliminate it.

Although bad breath is not usually serious, it can be an indicator of a medical disorder, such as a local infection in the respiratory tract, chronic sinusitis, postnasal drip, chronic bronchitis, diabetes, gastrointestinal disturbance, liver or kidney ailment. If your dentist determines that your mouth is healthy, you may be referred to your family doctor or a specialist to determine the cause of bad breath.

Bad breath can also be caused by dry mouth (xerostomia), which occurs when the flow of saliva decreases. Tobacco products also cause bad breath. If you use tobacco, ask your dentist for tips on kicking the habit.

Maintaining good oral health is essential to reducing bad breath. Schedule regular dental visits for a professional cleaning and checkup. If you think you have constant bad breath, keep a log of the foods you eat and make a list of medications you take. Some medications may play a role in creating mouth odors. Let your dentist know if you've had any surgery or illness since your last appointment.

Brush twice a day with fluoride toothpaste to remove food debris and plaque. Brush your tongue, too. Once a day, use floss to clean between teeth.

Mouthwashes are generally cosmetic and do not have a long-lasting effect on bad breath. If you must constantly use a breath freshener to hide unpleasant mouth odor, see your dentist. If you need extra help in controlling plaque, your dentist may recommend using a special antimicrobial mouth rinse. A fluoride mouth rinse, used along with brushing and flossing, can help prevent tooth decay.
Jonathan B. Levine, DMD
While it remains a mystery why some of us have worse breath than others, there are factors that can exacerbate the condition even more. And some are more obvious than others.

  • Thick saliva: The thicker your saliva, the less oxygen it contains. The less oxygen it contains, the less fresh your mouth -- and breath -- will be.
  • Smoking: A top culprit for dry mouth.
  • Alcohol: Another agent which can promote dry mouth.
  • Prescription medications and antihistamines: Both have drying effects on the mouth.
  • Old, worn dental work: If your old dental work (old composites, old silver fillings or old crowns) has a slick surface (versus a rough one), bacteria are more likely to colonize there. When dentistry causes more problems and harm to a patient than if it had never been done at all, this kind of counter-productive dentistry is called iatrogenic dentistry. I'd say about fifty to sixty percent of the dentistry that's performed is unfortunately, iatrogenic.
  • Gastric reflex: Bad breath can be caused by gastric juices, which is hard to solve, but can be done. Ask your doctor about prescribing a medication to get this condition under control.
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Joan Haizlip, MSN
Cardiology (Cardiovascular Disease)
Halitosis can be caused by rotting food that gets stuck in your mouth if you don’t brush after meals. Rotten food also helps bacteria grow and this can lead to gum disease (gingivitis). Gingivitis can also cause bad breath.
Dr. Mehmet Oz, MD
Cardiology (Cardiovascular Disease)
Bad breath can be more than just an annoyance -- it could mean a serious medical problem. In this video, Dr. Chutkan and I discuss the connection between bad breath and certain diseases. 
Randolph P. Martin, MD
Cardiology (Cardiovascular Disease)
Bad breath can be caused by plaque build up, left over food substances, or bacteria around your gums, but the chief culprit of bad breath is the back of your tongue. Watch my video to learn more about what causes of bad breath.

Tom Berry
Oral & Maxillofacial Surgery

Halitosis or bad breath usually results from poor oral hygiene. Failure to brush and floss on a regular basis results in bacteria and food debris accumulation in the mouth. Odors can be given off by bacteria that are around the teeth, gums, and tongue and decaying food particles left in the mouth. Some bacteria may give off volatile sulfur compounds contributing to the odor.

Bad breath (halitosis) can be caused by many factors. The primary cause of bad breath is odor-producing bacteria on the back of the tongue. These bacteria generate volatile sulphur compounds and other noxious compounds from the foods you eat. In addition,  poor dental hygiene, gum disease and tooth decay are  causes.

Certain foods, such as onions and garlic are commonly known to cause bad breath.

Kidney disease, liver failure, and diabetes can cause your breath to have a a characteristic  odor which can be unpleasant.  Dry mouth caused by some prescription drugs or smoking, dieting, sinus infections, and lung infections can also cause bad breath.

While certain medical conditions, strong foods (such as garlic and onions) and smoking account for a small percentage of the causes of bad breath, the overwhelming cause of halitosis is poor oral health.

Bacteria that grow in the mouth and on the tongue cause the foul-smelling odor. The bacteria create volatile sulfur compounds. These compounds can be a result of postnasal drip, faulty dental work, impacted wisdom teeth, gum disease or spaces between teeth where food may accumulate
Bad breath (halitosis) can be caused by many factors. Certain foods such as onions and garlic are commonly known to cause bad breath. Rotting food can cause sulpher compounds created by bacteria. Gum disease, poor dental hygiene, and tooth decay are primary causes.

Kidney disease, liver failure, and diabetes can cause your breath to have a strange odor. Dry mouth caused by some prescription drugs or smoking, dieting, sinus infections, and lung infections can also cause bad breath.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.