Most adults suffer from bad breath occasionally, although it may affect up between a quarter and half of adults on a regular basis.
Occasional bad breath is usually caused by strong foods like garlic, onions and coffee.
Persistent bad breath is usually brought on by the breakdown of proteins by bacteria somewhere in the mouth, usually as a result of gum disease or dry mouth.
However, problems with the airways, oesphagus and stomach can also lead to bad breath.
Smoking causes its own type of bad breath as well as leading to higher levels of gum disease and dry mouth.
Factors that affect the mouth and cause bad breath:
1)Gum disease -- 2)Food stagnation between the teeth -- 3) A dry mouth, which can be common as we get older and is also caused by a number of medications.-- 4)Excessive bacterial activity on the tongue, possibly due to postnasal drip-- 5)Throat or tonsil infection.