Online Dental Education Library

Our team of dental specialists and staff strive to improve the overall health of our patients by focusing on preventing, diagnosing and treating conditions associated with your teeth and gums. Please use our dental library to learn more about dental problems and treatments available. If you have questions or need to schedule an appointment, contact us.

What causes bad breath?

Bad breath is caused by a variety of factors. In most cases, it is caused by food remaining in the mouth - on the teeth, tongue, gums, and other structures, collecting bacteria. Dead and dying bacterial cells release a sulfur compound that gives your breath an unpleasant odour. Certain foods, such as garlic and onions, contribute to breath odour. Once the food is absorbed into the bloodstream, it is transferred to the lungs, where it is exhaled. Brushing, flossing and mouthwash only mask the odour. Dieters sometimes develop unpleasant breath from fasting.

Periodontal (gum) disease often causes persistent bad breath or a bad taste in the mouth, and persistent bad breath may mean a sign that you have gum disease.

Gum disease is caused by plaque - the sticky, often colorless, film of bacteria that constantly forms on teeth. Dry mouth or xerostomia may also cause bad breath due to decreased salivary flow. Saliva cleans your mouth and removes particles that may cause odor. Tobacco products cause bad breath, stain teeth, reduces your ability to taste foods and irritate your gum tissues. Bad breath may also be a sign that you have a serious health problem, such as a respiratory tract infection, chronic sinusitis, postnasal drip, chronic bronchitis, diabetes, gastrointestinal disturbance, liver or kidney ailment.

Here are characteristic bad breath odours associated with some of these illnesses:

  • Diabetes - acetone, fruity
  • Liver failure - sweetish, musty
  • Acute rheumatic fever - acid, sweet
  • Lung abscess - foul, putrefactive
  • Blood dyscrasias - resembling decomposed blood
  • Liver cirrhosis - resembling decayed blood
  • Uremia - ammonia or urine
  • Hand-Schuller-Christian disease - fetid breath and unpleasant taste
  • Scurvy - foul breath from stomach inflammation
  • Wegner`s granulomatosis - Necrotic, putrefactive
  • Kidney failure - ammonia or urine
  • Diphtheria, dysentery, measles, pneumonia, scarlet fever, tuberculosis - extremely foul, fetid odor
  • Syphilis - fetid

Bad breath may also be caused by medications you are taking, including central nervous system agents, anti-Parkinson drugs, antihistamines/decongestants, anti-psychotics, anti-cholinergics, narcotics, anti-hypertensives, and anti-depressants.

Caring for bad breath

Daily brushing and flossing, and regular professional cleanings, will normally take care of unpleasant breath. And don't forget your often overlooked tongue as a culprit for bad breath. Bacterial plaque and food debris also can accumulate on the back of the tongue. The tongue's surface is extremely rough and bacteria can accumulate easily in the cracks and crevices.

Eliminating periodontal disease and maintaining good oral health helps to reduce bad breath. If you have constant bad breath, make a list of the foods you eat and any medications you take. Some medications may contribute to bad breath.

Improperly cleaned dentures can also harbour odour-causing bacteria and food particles. If you wear removable dentures, take them out at night and clean them thoroughly before replacing them.

If your dentist determines that your mouth is healthy and that the odour is not oral in nature, you may be referred to your family physician or to a specialist to determine the cause of the odor and possible treatment. If the odor is due to gum disease, your dentist can either treat the disease or refer you to a periodontist, a specialist in treating gum tissues. Gum disease can cause gum tissues to pull away from the teeth and form pockets. When these pockets are deep, only a professional periodontal cleaning can remove the bacteria and plaque that accumulate.

Mouthwashes are generally ineffective on bad breath. If your bad breath persists even after good oral hygiene, there are special products your dentist may prescribe.   


Dentist Winnipeg MB

Dentist - Winnipeg
344 Marion Street
Winnipeg, MB R2H0V3
(At Enfield Crescent)
204-235-0085
[email protected]

Map & Directions