Most people can smell other people's breath, but have trouble smelling their own

A main problem with bad breath is that the only person not to notice it is the person affected. (You get used to your own smell and do not tend to notice your own bad breath.) Often, the only way to know about it is if a person comments on it. However, most people are too polite to comment on another person's bad breath. You may have to rely on a family member or a close friend to be honest and tell you if you have bad breath.
 
 Perhaps you could ask your dentist next time you have a check up. A dentist will normally be able to say if you have bad breath. Gum disease is a common cause of bad breath and a dentist will be able to advise on treatment if you have gum disease.
 
 Some people suggest a simple test which you can do yourself to detect bad breath. Lick the inside of your wrist. Wait a few seconds for the saliva to dry. Then smell the licked part of the wrist. If you detect an unpleasant smell you are likely to have bad breath.