Why Bad Breath Happens

Bad breath, known clinically as halitosis, affects most people at some point. Occasional bad breath after strong foods, coffee or first thing in the morning is normal. Persistent bad breath that does not improve with brushing usually has an underlying cause that can be identified and treated.

Many causes of persistent bad breath originate in the mouth. Bacteria that build up on the tongue, between teeth and below the gum line release sulphur compounds that cause the odour. Because the cause is usually local, treatment is often very effective once the source is found.

Common Causes

• Plaque and tartar build up, particularly below the gum line where deposits cannot be completely removed by brushing alone. A professional clean removes these deposits.
• Gum disease, one of the most common causes of persistent bad breath. Read more about gum disease signs and treatment.
• Tooth decay or damaged or deteriorating restorations that trap food and bacteria, which may need restorative treatment.
• Dry mouth, often linked to medications, mouth breathing or dehydration. Saliva naturally rinses bacteria away, so less saliva means more odour.
• Coated tongue, where bacteria collect on the back of the tongue.
• Diet, smoking and alcohol, which affect both odour and saliva flow.
• Broader non-dental or medical causes, such as sinus infections, tonsil stones, gastrointestinal factors or other underlying health conditions. If your mouth is healthy and bad breath persists, we may recommend seeing your GP or another healthcare practitioner for further assessment.

How We Find the Cause

At your examination we assess your teeth, gums and tongue, check for decay, damaged or deteriorating restorations and gum pocketing, and talk through your diet, medications and daily habits. Digital imaging can reveal hidden decay or infection that is not visible in the mirror. Identifying the actual source matters, because masking odour with mouthwash does not treat the cause.

Treatment and Prevention

Treatment depends on the cause. It may include a professional clean, gum treatment, repairing decayed teeth, or advice on managing dry mouth. At home, brush twice daily, clean between your teeth every day, clean your tongue with a scraper or soft brush, drink water regularly and limit smoking and alcohol. Patients may notice an improvement once the underlying cause is addressed, although results vary between individuals.

Frequently Asked Questions