Bad Breath: Various Causes, Treatment and Precautions for Halitosis

Are you suffering from bad breath? If yes, it can be a big cause of embarrassment for you, when in parties or when among friends.  In this article let’s try to find out various causes, and treatment options for bad breath. We will also have a look at the mechanism of production of foul breath and how to prevent it from happening.

Let’s jump right in.

Did you know that bad breath is called ‘Halitosis’ in medical terms? Halitosis refers to bad breath, emanating from the mouth.

The word ‘Halitosis’ is derived from Latin, in which ‘halitus’ means ‘breath’ and ‘osis’ means ‘condition or pathological state’. It is also called fetor exore or fetor oris.

Don’t mistake Halitosis or bad breath for a disease. It isn’t a disease. It’s just a symptom. It is also one of the most commonest clinical problems encountered in dental practice by the dentist.

The reason for halitosis is often evident in the mouth like a decayed tooth or an abscess. If that’s not the case the bad breath may be a result of a systemic condition like a lung abscess, acid peptic disease, suppurative pharyngitis etc.

And then there are some cases, where the person feels that he or she has halitosis even after having a good oral hygiene and goes from one doctor to another, only to hear that everything is normal and they don’t have halitosis. The reason may be ‘delusional halitosis’.

Let’s explore all of these reasons for bad breath in detail.

bad breath

Bad Breath Causes and Classifications

As mentioned earlier, halitosis is a symptom, not a disease. The main reasons for halitosis can be broadly classified into 3 categories.

  • Physiologic
  • Systemic
  • Psychogenic

Physiologic Causes of Bad Breath

These are the causes that are related to the normal physiology of the body.

Pregnancy: The occurrence of halitosis in pregnant women is a normal phenomenon. It may be related to pregnancy gingivitis or the hormonal changes that take place in the woman’s body during pregnancy.

Starvation: If you haven’t eaten anything for a long time (longer than normal) you might experience bad breath. This is also called ‘Hunger breath’.  This is due to putrefaction( the process of decay or rotting in the body) of Pancreatic juices in the stomach during starving.

Xerostomia: Xerostomia is a condition where there is a lack of Saliva in the mouth. Bad breath is a common phenomenon in people suffering from Xerostomia.

Food Items: The type of food we intake also has a vital role to play when it comes to halitosis. Here are some food items which are known to cause bad breath in individuals.

  • Spicy food
  • Meat: In some people, the degraded waste products of ingested Protein (Meat, in this case) may be eliminated through the lungs. Meat is a very common example in this category which contains fat and volatile fatty acids. Onion, Garlic, Fish, and Alcohol also belong to this category.
  • Vitamin C deficiency is also known to cause Halitosis in many people.

Drugs or Medications: Yes. Many medications we intake are known to cause bad breath among patients. Below are some of the drugs which are known to cause Halitosis.

  • Isosorbide Dinitrate
  • Drugs containing Iodine and Chloral Hydrate
  • Diuretics
  • Antineoplastic drugs such as Methotrexate, Adriamycin Bleomycin etc. may cause mouth ulcers, candidiasis, periodontal breakdown and the dry mouth leading to halitosis.

Systemic Causes of Halitosis

Systemic causes are problems that have arisen due to issues in the overall system rather than a specific, isolated factor in our body.

Blood and Blood Disorders: In people suffering from bleeding disorders such as Haemophilia, and Thrombocytopenia there may be decomposition of blood resulting from spontaneous bleeding leading to bad breath.
Halitosis is also common in patients with Anemia.

Otitis Media: The middle ear infection is also associated with the presence of bad breath in individuals.

Respiratory System: Here are some of the respiratory conditions which may result in Halitosis.

  • Rhinitis
  • Chronic Sinusitis
  • Laryngitis
  • Lung abscess
  • Bronchitis
  • Bronchiectasis
  • TB
  • People who are suffering from lung abscess or bronchiectasis have breath that is described as that of odorous rotting meat.

Gastrointestinal Tract: Below, are the conditions related to our Gastrointestinal Tract or the digestive system that may result in bad breath.

  • Poor oral hygiene is the most common cause of bad breath.
  • Gingivitis
  • Periodontal disease
  • Pericoronitis
  • Impaction of food in between teeth
  • Extraction wounds
  • Dry socket
  • Anaerobic infection
  • Patients undergoing endodontic treatment
  • Pharyngitis
  • Reflux oesophagitis
  • Peptic and Duodenal ulcers
  • Hemorrhage in GIT
  • Indigestion
  • Severe hepatic failure (described as fresh cadaver smell)
    Special care should be taken to rule out the possibility of oral malignancy, tonsillitis, and xerostomia when the proper reason for halitosis hasn’t been established yet.


Cardiac: The cardiac conditions which may cause foul breath are

  • Rheumatic fever (the breath is described as acid sweet breath)
  • Cor pulmonale

Renal: Here are some of the reasons related to Kidney and related systems which can cause bad odor in the mouth.

  • Renal failure
  • Nephrotic syndrome
  • Uremia
  • Kidney failure
    In these conditions, there may be ammonia smell in the breath which is similar to the smell of urine.

Endocrine and Metabolic Causes of Foul Breath

  • Hypothyroidism and Hyperthyroidism. Click here to read about hypothyroidism.
  • Patients suffering from Diabetes mellitus may have acetone breath, due to excretion of acetone through lungs.
  • People who have low Basal metabolic rates (B.M.R) tend to have lower saliva secretion in the night during sleep. This may result in accumulation and putrefaction of epithelial cells, debris and saliva in the mouth resulting in Halitosis.

Psychogenic Factors

In some rare cases, the person thinks that he/she has bad breath and seeks professional help. These people have a tendency to repeatedly visit their dentist and demand oral prophylaxis or teeth cleaning.

These people actually aren’t suffering from Halitosis and have good oral hygiene. But they won’t trust you if you say that to them.

In severe cases, they may need professional counseling, anxiolytics, and antidepressants after consultation with the doctors.


Xerostomia is a condition where there is the partial or complete absence of salivary secretion in the mouth. Xerostomia can happen due to many reasons like radiation therapy, salivary gland disorders, hormonal problems, malignancy etc.
As there is a lack of cleaning action of Saliva in the mouth, Halitosis is a common finding in these conditions.

Can You Measure Bad Breath?

Yes. You can. Bad breath can be measured using the following techniques and instruments.

  • Osmoscope
  • Breath analyzers
  • High-performance gas chromatography
  • Mass spectrometric analysis of volatile Sulfur compounds

If a person is suffering from foul odor of mouth he or she will have the following findings from the above tests.

  • Hydrogen sulphide is the highest
  • Methyl mercaptan is the next highest but is the most objectionable and smelly at lower concentrations.
  • Dimethyl sulphide is the next highest which is only a minor component.

Can Mouthwashes Used for Bad Breath Be Harmful?

Yes. Mouthwashes can cause significant damage to our health if not used properly. Kozlovsky A. and team conducted studies and found that indiscriminate use of mouthwashes may actually promote Halitosis.

They also found that acute toxicity of mouthwashes exceeds the toxic effects of alcohol, if not used in correct amounts and number. So use your mouthwashes properly for optimum results. Overuse can do more harm than good.

Treatment Options for Bad Breath and Precautions

  • Use of commercial oral rinses is an effective treatment for bad breath. But overuse will aggravate the problem.
  • One needs to maintain proper oral hygiene if he/she wants to get rid of halitosis. Use of Waterpik, electric toothbrushes and good foaming toothpaste can greatly help.
  • Avoid the use of antibiotic mouth rinses as they can harm the normal and beneficial microorganisms in our mouth which play a vital role in preventing growth and multiplication of disease-causing organisms.
  • A one time use of Chlorine dioxide mouthwash improves mouth odor pleasantness and reduces bad breath intensity for at least the next 4 hours.
  • Commercial dentifrices or toothpaste containing Triclosan and a Copolymer are efficient in controlling Halitosis for long hours.
  • Look for toothpaste that has pure solvent glycerol and polyethylene with triclosan dissolved in it.
  • Full strength oxidizing lozenges, chewing gums, and breath mints are quite effective in reducing bad odour.
  • Even chewing gums can temporarily control bad breath. This is more useful if chewing gums have Zinc component in them.
  • Using flavoured mouth rinses can be a great way to cure bad odour temporarily.
  • Mouth rinses containing Cysteine should be avoided. Why? Because Cysteine is known to produce volatile sulphur compounds which are the main cause of bad odour in the mouth.
  • As mentioned earlier mouthwashes should be used with utmost precaution. Instructions should be followed strictly regarding the frequency and the amount of usage. If proper amounts are not used and if the intervals between two usages aren’t followed strictly, these mouthwashes can result in stomatitis and desquamation of mucosa in the mouth.
  • Xerostomia or the dryness of the mouth should be managed properly by using drugs like Pilocarpine. Pilocarpine is a drug which induces saliva flow from the glands. Even artificial salivary substitutes can be used, with a doctor’s consult.
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Medical Disclaimer

This content is strictly the opinion of the author and is for informational and educational purposes only. It is not intended to provide medical/dental advice or to take the place of medical advice or treatment from a personal physician or a dentist. All readers/viewers of this content are advised to consult their doctors or qualified health professionals regarding specific health questions.

The publisher of this content takes NO responsibility for possible health consequences of any person or persons reading or following the information in this educational content. All viewers of this content, especially those taking prescription or over-the-counter medications, should consult their physicians and/or the dentists before beginning any nutrition, supplement, medications or lifestyle program.

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