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Bad Breath (Halitosis): Causes and Cures

Bad breath, medically known as halitosis, occurs when decaying food particles or other debris accumulate in the mouth and are consumed by the bacteria normally present in the mouth to produce an unpleasant odor. Another possible cause of bad breath is nasal discharge or mucus, which can accumulate at the back of the throat, promoting the growth of bacteria and producing foul breath. In addition, certain foods and beverages, such as onion, garlic, alcohol or coffee, when digested, release a distinctive odor from the lungs to the breath as a person exhales. This continues until the molecular components of these products have been completely eliminated from the body.

Bad breath (halitosis) is very common, affecting almost one third of the population. In many people it occurs upon waking in the morning. This is caused by a decrease of saliva in the mouth during sleep, which helps to rid the mouth of decaying food particles, dead cells and bacteria that normally accumulate there.

Most of the time, bad breath is a temporary problem and it is resolved when saliva production is restored in the morning, or when certain foods or beverages exit the body, or when foul breath caused by poor dental hygiene is professionally treated. However, bad breath can also be chronic and can signal an underlying medical condition. Sometimes, a person believes they have foul breath though the odor cannot be detected by anyone else. This may indicate a psychological problem called pseudo-halitosis.

Potential Causes of Bad Breath

In most cases, bad breath is caused by bacteria naturally occurring in the mouth, creating a foul-smelling odor in response to the presence of food particles or dead cells in the mouth. A lack of saliva and poor dental hygiene exacerbate this problem. The most common causes of foul breath include:

  • Abscessed tooth is one of the most common causes of halitosis.
  • Dry mouth. An abnormal dryness in the mouth from a lack of saliva may allow the build-up of food particles and other debris, causing bad breath. Other potential causes of dry mouth include symptoms of some medical conditions, side effects of certain medications and therapies, such as radiation therapy, or breathing through the mouth instead of the nose. Alcohol, including alcohol-based mouth rinses, and smoking tobacco can also contribute to drying out the mouth.
  • Oral infections due to gum disease, tooth decay and tooth abscess cause significant bacterial build-up in the mouth that often leads to halitosis.
  • External agents that may cause halitosis include certain foods and beverages (e.g., onions, garlic, cabbage, alcohol or coffee) as well as tobacco smoking. Tobacco use can also cause gum disease, further increasing the likelihood of bad breath among smokers. In addition, dentures, retainers and mouth guards can harbor food particles and odor-producing bacteria, causing foul breath.
  • Certain diets. Consuming few carbohydrates (e.g. during periods of fasting) can cause ketoacidosis, in which the body burns fat instead of carbohydrates for energy and releases odor-causing waste products in the breath. This produces breath with a sweet or fruity smell.

Non-oral causes of bad breath are less common and may include:

  • Digestive problems. A number of conditions involving the digestive system can cause bad breath, including bowel obstruction and gastroesophageal reflux disease (GERD).
  • Respiratory tract infections cause increased mucus levels that promote the growth of odor-causing bacteria, producing bad breath. These infections may include sinus, throat or lung infections.
  • Nasal obstruction resulting in nasal discharge at the back of the throat can lead to bad breath. This cause is common in children.
  • Kidney disease can also cause foul breath. When the kidneys fail to work properly, an ammonia-like odor in the breath can be produced.
  • Diabetes. Uncontrolled diabetes can result in fruity-smelling breath.

Symptoms of Halitosis Other than Foul-Smelling Breath

In many cases, patients with halitosis may not be able to detect the foul odor emanating from their mouth themselves. Therefore, they may only discover the condition based upon the reactions of others. However, there are also certain other symptoms than foul odor in the breath that may indicate the presence of halitosis such as:

  • Tooth decay
  • Food particles, plaque or tartar on the teeth
  • Dry mouth
  • Swollen gums
  • Open sores inside the mouth
  • Bad taste in the mouth
  • Drainage from the mouth
  • Cold or flu-like symptoms (e.g., sore throat, fever)
  • Signs of an underlying medical condition (e.g., vomiting due to a bowel obstruction or heartburn due to acid reflux)

Treatment and Prevention of Bad Breath

Successful treatment of bad breath largely depends on identifying and treating its cause. Most often, this means receiving the appropriate dental treatment (e.g., treatment for tooth decay, abscesses or gum disease). Remember that over-the-counter products, such as scented toothpastes, mouthwashes, sprays, gum or mints, despite making bold claims, do not actually treat halitosis, they only mask it. These remedies do not address the underlying problem and their effects are merely temporary.

Other methods of treating and preventing bad breath include:

  • Regular visits to the dentist can reveal oral infections (e.g., from tooth decay) that are the source of bad breath. In addition, periodic teeth cleanings can help prevent other problems resulting in foul breath.
  • Proper daily dental hygiene, including brushing the teeth, tongue and gums, flossing and special mouth rinses, helps to keep the mouth free of food particles and other debris that may lead to halitosis.
  • Plaque prevention alternatives include eating foods such as apples, raw carrots, celery, parsley or mint leaves to help prevent the build-up of plaque in the mouth when a person for some reason is unable to perform proper dental hygiene.
  • Stimulating saliva production by chewing sugar-free gum and sucking on sugar-free candy or lozenges. Saliva helps to rid the mouth of odorous germs. In some cases, an artificial saliva spray or gel may be prescribed by a dentist.
  • Avoiding triggers such as garlic, onions, cabbage, coffee, alcohol and tobacco that may be responsible for causing bad breath.
  • Periodically replacing toothbrush every few months to reduce bacterial build-up on brushes can help prevent developing halitosis.
  • Keeping oral devices clean. Daily cleaning of dentures, retainers or mouth guards prevents the build-up of bacteria and/or food particles on the oral equipment, which can contribute to bad breath.
  • Drinking plenty of fluids helps wash away germs, encourage saliva production and dilute concentrations of the smelly waste products released in the breath.

When bad breath is a symptom of an underlying medical condition (e.g., digestive disease, kidney failure, respiratory problem or diabetes) the condition itself must be treated to eliminate the halitosis.

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