Halitosis, or foul breath, can be a problem for many and is caused by odour producing bacteria in either the oral or nasal cavities. The bacteria causing the bad odour may reside in areas of decay, gum disease or the back portion of the tongue. The rst step to solving the bad odour is a visit to your dental professional for a cleaning and evaluation of your homecare. Follow up with your dentist about concerns you may have associated with bad breath because dry mouth and other medical issues may contribute to this condition.