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Bad breath (halitosis)

bad; breath; halitosis; tooth; teeth; tongue; caries; gingivitis;


Have you ever been talking to someone and had to turn away because their breath smelt really bad? Has anyone done that to you?

Most healthy people have unpleasant smelling breath sometimes, especially when they wake up, but only a few people have bad breath (halitosis) most of the time. If people have really bad breath it can have a big effect on their social life and what other people think about them, but many people worry unnecessarily about their breath.

Causes of bad breath

  • The usual cause of bad breath is sulphur compounds made by bacteria when they break down the remains of food in the mouth.
    • Most people have large numbers of bacteria in their mouth, and they have even more if they have dental plaque because they have not cleaned their teeth well enough. These bacteria usually do not cause infections or illness.
    • Bacteria can also form a white, grey or yellowish coating on the tongue in some people.
    • Infections in the gums (gingivitis), tonsils, sinuses and nose mean there are even more bacteria to cause the bad smell.
    • Having a very dry mouth means that there is less saliva to wash away bacteria.
  • People who are on extreme diets (such as people on very high protein diets or who have anorexia nervosa) have bad breath.
  • Some of the popular low carbohydrate, high protein diets cause bad breath in almost everyone who follows them.
  • Some foods, such as garlic, onions and curry will cause a change in the smell of your breath for a short time.
  • Smokers have unpleasant smelling breath.
  • People who need to breathe through their mouth most of the time (perhaps due to sinusitis) will have a dry mouth, and may have bad breath.
  • Some medicines can cause bad breath.
  • Some health problems, such as liver disease, kidney disease, lung diseases and diabetes can change the smell of breath.

Signs of bad breath

  • It is not really possible to smell your own breath, not even by breathing into your cupped hands, so you need to listen to what other people say about your breath.
  • Some people say they have an unpleasant, metallic taste when they have bad breath.
  • Some people with bad breath have a white or greyish coating on their tongue. Not everyone with this coating has bad breath.

Remember that most people have 'bad breath' when they wake up, so don't worry about that. A drink of water will help clean your mouth.

What to do if you have bad breath

  • Make sure that you clean your teeth well. Use fluoride toothpaste and a soft toothbrush to clean your teeth twice a day. You could brush your tongue at the same time.
  • Floss between your teeth (get your dentist or dental therapist to show you how to do this).
  • Avoid foods that are sticky and high in sugars. Bacteria love sugary food that sticks to your teeth!
  • Have a drink of water after eating, and whenever your mouth feels dry.
  • Mouth washes and breath fresheners can hide bad breath for a little while, but they don't get to the cause of the problem and their effects do not last. They are also rather expensive.
  • If you are a smoker, try to kick the habit! Smelling like a dead ashtray can be rather off-putting!

See your dentist or dental therapist

Your dentist or dental therapist will be able to check the health of your mouth and teeth, and give you advice about dental hygiene and any treatment you might need.

See your doctor

Since there are several health problems that can cause bad breath, have a talk to your doctor too if you are worried by bad breath.

More information

Better Health Channel


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The information on this site should not be used as an alternative to professional care. If you have a particular problem, see a doctor or other health professional.
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