What causes bad breath?

Bad Breath

Bad breath is typically caused by food remaining in the mouth collecting bacteria on your teeth, tongue, gums and other structures. Dead and dying bacterial cells release a sulfur compound giving your breath an unpleasant odour. Certain foods, including garlic and onions also contribute to breath odour. Once the food is absorbed into your bloodstream, it is then transferred to your lungs, where it is exhaled. Brushing, flossing and mouthwash only mask this odour.

Mouthwashing is generally ineffective for bad breath. If your bad breath persists despite good oral hygiene, there are special products our dentist may prescribe.

Gum Disease

Gum disease often causes persistent bad breath or a bad taste in the mouth, while persistent bad breath can be a sign of gum disease.

Gum disease is caused by plaque -- the sticky, colourless, film of bacteria that forms on teeth. Saliva cleans your mouth and removes particles that may cause odour, therefore dry mouth can cause bad breath due to decreased salivary flow. Tobacco products also cause bad breath, stain teeth, reduce your ability to taste foods and irritate gum tissues.

Bad breath odours associated with other illnesses

Bad breath may also be a sign of a serious health problem, such as a respiratory tract infection, chronic sinusitis, postnasal drip, chronic bronchitis, diabetes, gastrointestinal disturbance, liver or kidney ailment.

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

  • 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 odour
  • Syphilis - fetid

    Caring for bad breath

    Daily brushing and flossing, combined with regular professional cleanings, typically take care of unpleasant breath. Bacterial plaque and food debris also can accumulate on the back of the tongue, so remember to brush your tongue as part of your dental hygiene routine. The tongue's surface is rough therefore bacteria easily accumulate in cracks and crevices.

Eliminating gum disease and maintaining good oral health help 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 our 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 odour and possible treatment. If the odour is due to gum disease, our dentist can either treat the disease or refer you to a specialist in treating gum tissues. Gum disease can cause gum tissues to pull away from teeth and form pockets. When these pockets are deep, only a professional gum cleaning can remove accumulated bacteria and plaque.