Bad breath (halitosis) is a common presenting complaint and we find patients are often embarrassed and often unsure about what to do or the cause. In actual fact, most people experience bad breath from time to time. Bad breath is caused by the waste product bacteria produce when they lie stagnant in our mouths for prolonged periods of time (volatile sulfur compounds.)  Seeing as all of us (except for newborns) have bacteria colonised in our mouths, bacteria waste product is unavoidable.