Bad breath (or halitosis) is the name given to unpleasant odours exhaled when breathing. Bad breath can have a significant and negative impact, both personally and socially, on those who suffer from it. This fact sheet explains the causes of bad breath, and the steps you can take to reduce or prevent it.
What causes bad breath?
In most cases, bad breath originates in the mouth itself. The intensity of bad breath can change during the day, as a result of eating certain foods, smoking, alcohol consumption and/or dryness of the mouth. Because saliva flow decreases during the night, bad breath is also common first thing in the morning.
Bad breath can have many causes such as gum disease, tooth decay, poor oral hygiene, smoking, consuming certain food and drinks, infections and gastric reflux. A dental professional can help identify the cause and offer solutions.
Sources of bad breath
- Mouth: Most cases of bad breath arise from naturally occuring bacteria in the mouth acting on trapped remnants of food and dead skin cells. Large quantities of bacteria are often found on the back of the tongue, as this part of the tongue is relatively dry and usually poorly cleaned. Gum disease can also cause bad breath. Bacteria thrives below the gumline and releases a foul smell as it acts on the infected tissues.
- Nose: The second major source of bad breath is the nose. Nasal odour may be due to sinus infections or the presence of foreign bodies.
- Tonsils: Bad breath can be caused by tonsillitis.
- Systemic diseases: People with systemic medical conditions may experience bad breath. These conditions include:
- chronic liver failure
- lower respiratory tract infections (bronchial and lung infections)
- kidney infections or kidney failure
- trimethylaminuria ('fish odour syndrome')
- diabetes, and
- problems with metabolism.
Conditions involving the regurgitation of stomach acids, such as gastric reflux, can also cause bad breath.
Factors which contribute to bad breath
- Inadequate water intake
- Dry mouth
- Drinking alcohol
- Breathing through your mouth
- Illnesses such as tonsillitis
- Medical conditions such as diabetes and kidney/lower respiratory tract infections
How can I minimise bad breath?
Practice good oral hygiene, including brushing, daily flossing, and regular visits to your dental professional. If you have dentures, clean and soak them overnight in an antibacterial solution (unless otherwise advised by your dental professional).
Gently clean the surface of your tongue twice a day with a tongue brush, tongue scraper or tongue cleaner to wipe off bacteria, debris and mucus.
Eat a healthy diet. Be aware that certain foods and drinks can cause bad breath eg. onions, garlic.
Make sure you drink lots of water during the day to prevent your mouth drying out. A dry mouth can increase bacterial build-up and cause or worsen bad breath.
Chewing sugar-free gum can increase saliva production and help reduce bad breath. Saliva washes away oral bacteria, has antibacterial properties and promotes chewing which helps cleanse the mouth.
Mouth rinses often contain antibacterial agents. Other rinses rely on odour eliminators like oxidizers which will prevent bad breath on a short-term basis. The use of essential oils in mouth rinses is also effective in reducing bad breath. Some mouth rinses contain alcohol, which has a drying effect and can actually worsen the problem.
While the use of mints helps to mask bad breath, frequent consumption can increase the risk of tooth decay due to their sugar content. It is important to seek advice from a dental professional to determine the cause of your bad breath. Your dental professional will be able to offer advice based on your individual needs and recommend products to treat the source of the problem.
For more information:
- contact your dental professional
- call 13 HEALTH (13 42 25 84) for confidential health advice 24 hours a day, seven days a week
- visit the Queensland Health Oral Health website