Common bad breath causes


According to the NHS direct around one in four people in the UK are thought to have bad breath (halitosis) on a regular basis with the most common cause of bad breath being:

Bad breath in the mornings

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.

Dry mouth

Bad breath associated with a dry mouth is caused by a reduction in the cleansing mechanism of the mouth as a result of reduced flow of saliva. There are many causes of a dry mouth. Dry mouth may also occur:

  • Due to a lack of fluid in the body (dehydration).
  • As a side-effect of some medicines (for example, tricyclic antidepressants).
  • As a symptom of some diseases (such as Sjögren’s syndrome).
  • Following radiotherapy to the head and neck region.

Foods, drinks and medicines

Foods such as garlic, spicy foods and alcoholic drinks and medicines can cause a smell on the breath. This type of bad breath is temporary and easily cured by not eating the food.


The only way to stop your breath from smelling like an ashtray through smoking is to quit. Smoking also increases the risk of developing gum disease which is another cause of bad breath.

Crash dieting or fasting

Most people may be surprised to hear this but dieting and fasting can cause a sickly sweet smell on the breath. This is due to chemicals called ketones being made by the breakdown of fat. Some ketones are then breathed out with each breath.

Medical causes

Some people with nasal problems can get bad breath. For example, a lump (polyp) in the nose, sinusitis or a small object stuck in a nostril (occurs most commonly in children) can cause a bad smell. Infections or tumours of the lung, throat, mouth or tonsils are sometimes a cause.

How to treat bad breath

Improving oral hygiene is usually enough to cure bad breath and prevent it happening again but sometimes this can be due to health issues which you may be unaware of.

If you are concerned about bad breath then call the team at Cornerhouse Dental so we can advise you about ways to improve your oral health including:

  • regularly brushing your teeth and gums
  • flossing between your teeth
  • keeping your tongue clean