We probably all know someone who has bad breath, but very few people feel brave enough to discuss the problem. It is obviously a very delicate matter to tell someone they have bad breath.
There is always the risk that they will be offended or embarrassed and may never speak to you again! However, it is always worth remembering that the bad breath may be caused by any number of problems. Once the person knows they have bad breath, they can deal with whatever is causing it.
You could try talking to their partner or a family member, as the bad breath may be caused by a medical condition which is already being treated.
You may like to leave a leaflet where the person is likely to see it.