Bad breath, also called halitosis, can be quite embarrassing and in some cases may even cause tremendous anxiety. No wonder that most store shelves are overflowing with gum, mints, mouthwashes and other products designed for fighting bad breath. However, many of these products are only temporary measures because they do not address the very cause of the problem.


Bad breath odours do vary, depending on the source or the underlying cause. Some people worry too much about their breath even though they have little or no mouth odour, while others have bad breath and do not know it. It’s difficult to assess how your own breath smells, feel free to ask a close friend or relative to confirm your bad-breath questions.


Most bad breath starts in your mouth, and there are many possible causes. They include:

Food. The breakdown of food particles in and around your teeth can increase bacteria and cause a foul odour. Eating certain foods, such as onions, garlic and spices, also can cause bad breath. After you digest such foods, they enter your bloodstream, are carried to your lungs and do affect your breath.

Tobacco products. Smoking does cause its own unpleasant mouth odour. Smokers and oral tobacco users are also more likely to have gum disease which is yet another source of bad breath.

Poor dental hygiene. If you do not brush and floss daily, food particles do remain in your mouth, causing bad breath. A colorless, sticky film of bacteria (plaque) forms on your teeth. If not brushed away, plaque can irritate your gums and eventually form plaque-filled pockets between your teeth and gums (periodontitis). Your tongue can trap bacteria that produce odors. Dentures that aren’t cleaned regularly or don’t fit properly can harbor odor-causing bacteria and food particles.

Dry mouth. Saliva helps cleanse your mouth, removing particles that cause bad odors. A condition called dry mouth or xerostomia (zeer–o-STOE-me-uh) can contribute to bad breath because the production of saliva is decreased. Dry mouth naturally occurs during sleep, leading to “morning breath,” and it worsens if you sleep with your mouth wide open.

Medications. Some medications can indirectly produce bad breath by contributing to dry mouth. Others can be broken down in the body to release chemicals that can be carried on your breath.

Infections in your mouth. Bad breath can be caused by surgical wounds after oral surgery, such as tooth removal, or as a result of tooth decay, gum disease or even mouth sores.

Other mouths, nose and throat conditions. Bad breath can occasionally stem from small stones that form in the tonsils and are covered with bacteria that produce odor. Infections or chronic inflammation in the nose, sinuses or throat, contributed from the postnasal drip, also can cause the bad breath.

Other causes. Diseases, such as some cancers, and conditions such as metabolic disorders, can cause a distinctive breath odor as a result of the chemicals they produce. Chronic reflux of stomach acids (gastroesophageal reflux disease, or GERD) can be associated with bad breath.


Your dentist will likely smell both the breath from your mouth and the breath from your nose and rate the odor on a scale. Because the back of the tongue is most often the source of the smell, your dentist may also scrape it and rate its odor.

There are sophisticated detectors that can identify the chemicals responsible for bad breath, though these are not always available.


To reduce bad breath, help avoid cavities and lower your risk of gum disease, consistently practice good oral hygiene. Further treatment for bad breath can vary, depending on the cause. If your bad breath is thought to be caused by an underlying health condition, your dentist will likely refer you to your primary care provider.

For causes related to oral health, your dentist will work with you to help you better control that condition.

Dental measures may include:

Mouth rinses and toothpaste. If your bad breath is due to a build-up of bacteria (plaque) on your teeth, your dentist may recommend a mouth rinse that kills the bacteria. Your dentist may also recommend toothpaste that contains an antibacterial agent to kill the bacteria that cause plaque build-up.

Treatment of dental disease. If you have gum disease, you may be referred to a gum specialist (periodontist). Gum disease can cause gums to pull away from your teeth, leaving deep pockets that fill with odor-causing bacteria. Your dentist might also recommend replacing faulty tooth restorations, a breeding ground for bacteria.

Lifestyle and home remedies

To reduce or prevent bad breath:

Brush your teeth after you eat. 

Floss at least once a day. 

Brush your tongue. 

Clean dentures or dental appliances. 

Avoid dry mouth. To keep your mouth moist, avoid tobacco and drink plenty of water not coffee, soft drinks or alcohol, which can lead to a drier mouth. Chew gum to stimulate the saliva. For chronic dry mouth, your dentist may prescribe an artificial saliva preparation or an oral medication that stimulates the flow of saliva.

Adjust your diet. Avoid foods such as onions and garlic that can cause bad breath. Eating a lot of sugary foods is also linked with bad breath.

Regularly get a new toothbrush.

Schedule regular dental check-ups. See your dentist on a regular basis — generally twice a year — to have your teeth or dentures examined and cleaned.