According to several studies, bad breath symptoms affect around 30 to 50% of the world’s population, regardless of age and gender.1–3
Development of halitosis depends on several factors or causes. For example, a dry mouth can cause bad breath, especially when waking up — this is known as “morning halitosis”. However, this is a mild and temporary oral malodour and generally not regarded as a health issue.3
Other factors linked to halitosis may be simply categorized into causes of oral and non-oral origin.1
Oral causes
9 out of 10 cases of halitosis are caused by issues within the oral cavity, usually a bacterial imbalance in the mouth. This is attributed to the fact that more than 500 species of bacteria live in the mouth and most of them can produce volatile sulphur compounds (VSC), which are smelly gases mainly responsible for foul breath.1,4
For this reason, oral hygiene is a key factor to prevent halitosis. Poor oral cleansing causes bacteria and food remnants to accumulate forming plaques in the tooth and tongue. This can further result in tongue coating build-up, and gum and periodontal inflammation—commonly known as gingivitis and periodontitis. These oral diseases, along with caries and the use of dental prosthetics, are frequent halitosis triggers.1
Additionally, pathological dryness of the mouth, known as xerostomia, has negative effects on self-cleaning of the mouth, and inadequate cleaning of the mouth causes bad breath. Dryness may be caused by certain medical conditions, medications, ageing, smoking, among others.1,5
Non-oral causes
Around 8 to 10% of the halitosis cases are caused by a non-oral origin. For example, respiratory system problems, gastrointestinal diseases, hepatic diseases, haematological or endocrine system disorders and metabolic conditions can all be the causes of halitosis.1
Common non-oral causes of bad breath1,3
- Sinusitis
- Foreign body in the respiratory system
- Tonsillitis
- Bronchitis and other lung infections
- Lung cancer
- Pyloric stenosis
- Gastroesophageal reflux
- Malabsorption syndrome
- H. Pylori infection
- Hepatic disease
- Renal disease
- Infection
- Diabetes
Other causes
There are other causes of bad breath symptoms, these are often linked to personal lifestyle and habits.1
- Dietary products and foods —garlic, onions, and spiced foods cause unpleasant odour or halitosis.6
- Tobacco —smokers tend to have gum disease and foul breath.6
- Alcohol and other drugs —metabolism of these compounds may cause temporary bad breath.1
- Medication —antihistamines, antidepressants, diuretics, antiparkinsonian drugs, anticonvulsants, antipsychotic medications are medications strongly related to the development of halitosis.2
Prevention and treatment
Oftentimes, bad breath can be prevented and treated by maintaining good oral hygiene. This will lower the risk of cavities and gum disease.1
Daily brush your teeth, use dental floss and perform oral rinses with a mouthwash —particularly one containing chlorhexidine and zinc, which have proven 12-hour effect to counteract VSC formation.1,6,7