has a variety of causes including bacterial infections, medications and medical conditions, postnasal drip and poor oral hygiene - not brushing your teeth frequently.
In most cases bad breath comes from the gums and tongue. Some bacteria in your mouth may produce compounds that result in an odour. Certain foods, such as onions and garlic not only leave lasting odours in your mouth but are also absorbed into the bloodstream. The odours are then expelled from the lungs. Until these foods are eliminated from the body, mouthwash, chewing gum and toothpaste can only mask the odours on the breath.
For some people, a dry mouth causes bad breath. Dry mouth can result from taking antihistamines for allergies or a cold or from antidepressants. It can also result from localized infections, diabetes gastrointestinal disturbances, liver or kidney ailments.
The postnasal drip that streams down the back of your throat during sinus infections, colds and allergies can result in bad breath. Sometimes, tiny food nuggets lodge in the crypts of your tonsils or on the tongue and cause a foul odour.
But most bad breath is the result of poor oral hygiene. Basically that means not brushing or flossing teeth frequently enough. Bacteria that build up on the back of your tongue or in between your teeth are the main culprits. Certain types of bacteria love to breed on the tongue and in the crevices between the teeth.
Tobacco products cause bad breath. Smoking or chewing tobacco can cause a foul odour.
A simple test
to find out whether you have bad breath is to lick the inside of your wrist with the back of your tongue and wait for a few seconds until the saliva dries. If your wrist smells unpleasant, it's likely your breath does too.
If you still have bad breath after making changes to your dental hygiene, see your doctor. There may be a medical cause that needs investigating. Don't try to hide the smell of your breath before visiting your dentist or doctor, because it will make it more difficult for them to find out what's causing the problem.