Halitosis is also called bad breath, malodour, offensive or foul odour of the mouth. Halitosis could be normal or psychological. The normal would be typically seen in so called “morning breath” which results from enzymatic break down of cellular protein and amino acids. Other psychological origins of halitosis include hunger, dehydration or it may be related to ingestion of certain foods and may be a sign of other health problems.

This is a common complaint in adults; it is an unpleasant smell on your breath that other people notice when one speaks or breaths out. In most cases of persistent bad breath, the smell comes from a build-up of bacteria within the mouth in food debris due to plaque and gum disease or in a ‘coating’ on the back of the tongue.

A main problem with halitosis is that the only person not to notice is the person affected. Often the only way one know about it is if a person comments about it

Causes of Halitosis: this is classified into two

  • Local causes
  • Systemic causes


Poor oral hygiene: a)plaque and calculus containing bacteria resulting in gingivitis and periodontitis, b)coating on the back of the tongue due to lack of proper brushing which contains bacteria, this explains why halitosis occur even in patients with good oral hygiene.

Gingivitis and periodontitis: destructive effects of anaerobic bacteria causing offensive smell, also occult blood from gingivitis may degenerate resulting in foul odour

Dental caries: food packing within the cavity, which rot due to bacteria action resulting in odour.

Poorly fitting dental appliances

Oral candidiasis

Oral sepsis e.g tonsillitus, ANUG, NUP, necrotizing stomatitis, ulcers. Pericoronitis etc

Dry mouth (xerostomia)


Oral tumour

Smoking – which starve the mouth of oxygen

 Food stagnation: normal teeth brushing may not clear bit food which get stuck between teeth. The food then rots and becomes riddled with bacteria.


Certain food: eg. Garlic, spicy foods, alcoholic drinks, onion, beans, high proteinous diet. As food are digested, the chemical in the food can get into the blood stream, and goes to the lungs, which is given off in the breath.

Fasting: this is due to the dryness of the mouth and break down of fats releasing ketones, resulting in ketotic halitosis.

Nasal and sinus infections: eg Sinustis, nasal polyp, foreign body in the nasal cavity, post nasal drip into the mouth, URTI, bronchitis or pneumonia, tonsillitis and other tumors of the nasal tract.

Xerostomia: caused by side effect of various medications, salivary gland problems or continuous mouth breathing. Saliva is necessary to moisten and cleanse the mouth by neutralizing acids produced by plaque and washing away dead cells that accumulate on the tongue, gums and checks. If not removed these cells decompose and can cause bad breath.

Gastro esophgeal reflux

Systemic disease such as:-

Gastrointestinal diseases: eg diarrhea, constipation, indigestion etc

Diabetes mellitus especially uncontrolled condition, csn result in breakdown of fat resulting in ketone released to give ketolic halitosis.

Hepatic disease

Renal disease

Psychological factors: eg Depression, anxiety.

AETIOLOGY: The micro-organisms implicated in oral malodour are predominantly gram-negative; Gram positive bacteria have also been implicated.


A white coating on the tongue

Dry mouth and teeth

Post nasal drip and mucous

Morning bad breath and a burning tongue

Thick saliva and a constant need to clear the throat

Constant sour, bitter metallic taste

Lack of confidence and self esteem due to peoples’ reaction.

MORNING BAD BREATH: most people have some degree of bad breath after a night’s sleep. This is normal and occurs because the mouth tends to get dry and stagnate overnight. This usually clears when the flow of saliva increases soon after starting to eat breakfast.

PSYCHOGENIC HALITOSIS: the complaint of malodour in the absence of odour.

Complaints made by patients who think they have it, but do not have it

No evidence of oral malodour can be detected even with objective test

The symptom may be attributed to some form of delusion or monosymptomatic hypochondriasis (elf oral malodour halitophobia)

Other people’s behaviour or perceived behaviour such as covering of nose or averting the face is often misinterpreted. Many of such patients will adopt behaviours such as: covering their mouths when talking, avoiding or keeping the distance from people, avoiding social situations, using chewing gums, mints, mouthwashes, etc with no improvement. Frequent tooth brushing (usually “over-brushing”). Thus their oral hygiene is superb. Medical help may be sort to manage these patients.


Once the cause of the condition is discovered the patient is already treated half way.

Oral prophylaxis such as scaling and polishing will go a long way in eliminating the bacteria accumulation in the mouth.

Oral hygiene instructions: tooth brushing technique should be re-emphasised, vigorous cleaning of the tongue towards the back to eliminate the white coating, brushing at least twice daily with good tooth brush and fluoride containing toothpaste.

Use of tongue scrapper can also be useful

Tooth brushing and flossing after meals to eliminate debris and bacteria

Spend at least 2 minutes brushing the teeth and change toothbrush at least every 3 months.

Antimicrobial mouth rinses are very effective in eliminating the bacteria in the oral cavity (e.g. chlorhexdine 0.2%, Listerine etc), hydrogen peroxide in 1:4 dilution also eliminates the anaerobes within the oral cavity.

Treat every dental caries, periodontal disease, infections and other identifiable dental problems responsible for the odour

Drugs causing halitosis could be discussed with the physician to have alternatives

Avoid all odour producing foods or adjust to suit need

Stop smoking is only the cure for odour caused by smoking

Treat all systemic disorders responsible for halitosis e.g diabetes, URTI, gastrointestinal diseases.

Constant sipping of water keeps the mouth moist; chewing of sugar free chewing gums could also be effective.

Regular dental visits

A chat with the psychologist could help in cases where psychogenic halitosis is suspected


Although malodour has varying ranges of causes, careful assessment of the various local and systemic causes could help us arrive at a definite solution. Where a systemic cause is inferred, it may be necessary to involve the medical specialist in the management of the patient.

As clinicians we should not be quick to conclude that halitosis is psychological.

Dr Tola Eweka