• Refer all people with dental disease or suspected oral cancer.
• Manage any underlying causes of halitosis.
• If no pathological cause is identified:
• Offer self-care advice about oral hygiene and advise the person to visit their dentist if oral or denture hygiene is poor.
• Consider referring all people with halitosis (including those without a pathological cause) to a dentist for a full oral examination as some oral diseases may be difficult to diagnose by visual examination alone.
• Give advice on reducing risk factors for halitosis.
• Avoid foods and drinks known to cause transient halitosis — such as garlic, onion, and alcohol.
• Advise smoking cessation and to avoid chewing tobacco (for further information, see the CKS topic on Smoking cessation).
• Treat dry mouth by increasing fluid intake, sucking sugar-free sweets or chewing sugar-free gum. Consider the use of an artificial salivary substitute if these measures are insufficient.
• Advise that dentures should be left out at night, and that the person consults their dentist if they have problems with their dentures.
• Advise regular dental checks to ensure maintenance of oral hygiene.
• Empirical treatment with antibiotics and Helicobacter pylori eradication therapy are not recommended.
• For people without detectable halitosis:
• Offer reassurance.
• Suspect the possibility of pseudo-halitosis or halitophobia — particularly if they have good oral and dental health.
• Discuss referral for psychological therapy if halitophobia is severe.

• Explain that:
• Transient bad breath is common upon waking (morning breath) and resolves with eating or drinking, or upon brushing the teeth or rinsing the mouth with water.
• Persistent halitosis is commonly caused by accumulation of food debris and dental bacterial plaque on the teeth and tongue.
• Give advice on general oral hygiene measures.
• Brush teeth twice daily (particularly last thing at night).
• Clean the interdental spaces using an appropriate aid (floss, tape, sticks, or single-tufted brush).
• Reduce the frequency and amount of sugary food and drinks consumed. These should be limited to mealtimes and consumed not more than four times a day.
• Advise the person to seek advice from a dentist or dental hygienist if they have problems maintaining dental hygiene (for example with brushing or using interdental aids).
• Encourage regular dental checks to ensure maintenance of oral hygiene.
• Recommend or prescribe a trial of an antibacterial mouthwash and/or toothpaste if the above oral hygiene measures are insufficient (see Additional information).
• Improvement will indicate that the halitosis is related to oral hygiene.
• Consider tongue brushing — particularly for people with halitosis who have good oral hygiene and health.
• This can be done by gently brushing the surface of the tongue (in particularly the posterior region) with a soft headed toothbrush while brushing the teeth (with toothpaste). Although a proprietary tongue scraper can be considered, there is insufficient evidence to recommend one product over another.
• Excessive scraping should be avoided as this can cause damage and bleeding to the tongue.
• Care should be taken to avoid triggering the gagging reflex.
• Explain that non-antibacterial products (such as mints, flavoured/perfumed mouth sprays/rinses, and chewing gums) only provide transient masking of halitosis. They are no substitute for good oral hygiene.

• Urgently refer to an appropriate specialist, anyone with:
• Acute necrotizing ulcerative gingivitis. See the section on Acute necrotizing ulcerative gingivitis in the CKS topic on Gingivitis and periodontitis.
• Unexplained tooth mobility for more than 3 weeks.
• Unexplained ulceration of the oral mucosa or mass persisting for more than 3 weeks.
• Unexplained red and white patches (including suspected lichen planus) of the oral mucosa that are painful or swollen or bleeding.
• Unexplained or atypical enlargement of the gingivae (possibly indicative of leukaemia).
• Non-urgent referral to a dentist is required for people with:
• Clinically-apparent gingivitis that is not responding to standard oral hygiene measures.
• Periodontitis.
• Unexplained red and white patches (including suspected lichen planus) of the oral mucosa that are not painful, swollen, or bleeding.
• Poorly-fitted dentures.
• Poor oral or denture hygiene.
• Some experts recommend referring all people with halitosis (including those without pathological causes) to a dentist for a full oral examination, as some oral diseases (such as periodontitis) may be difficult to diagnose by visual examination alone.
• Refer non-urgently to an ear nose and throat specialist people with the following conditions in whom an oral cause has been excluded:
• Recurrent tonsillitis (see the CKS topic on Sore throat - acute).
• Sinonasal disease such as septal deviation, and frequent recurrent sinusitis (see the CKS topic on Sinusitis).
• For people with other persistent symptoms or signs related to the oral cavity in whom a definitive diagnosis of a benign lesion cannot be made, refer or follow up until the symptoms and signs disappear. If the symptoms and signs have not disappeared after 6 weeks, make an urgent referral.

For information on contraindications, cautions, drug interactions, and adverse effects, see the electronic Medicines Compendium (eMC) (http://emc.medicines.org.uk), or the British National Formulary (BNF) (www.bnf.org).