Concerns of bad breath may be divided into genuine and non-genuine cases. Of those who have genuine bad breath, about 85% of cases come from inside the mouth. The remaining cases are believed to be due to disorders in the nose, sinuses, throat, lungs, esophagus, or stomach. Rarely, bad breath can be due to an underlying medical condition such as liver failure . Non-genuine cases occur when someone feels they have bad breath but someone else cannot detect it. This is estimated to make up between 5% and 72% of cases.
The treatment depends on the underlying cause.Initial efforts may include tongue cleaning, mouthwash, and flossing.Tentative evidence supports the use of mouthwash containing chlorhexidine or cetylpyridinium chloride and maybe tongue cleaner.Treating underlying disease such as gum disease, tooth decay, or gastroesophageal reflux disease may help. Counselling may be useful in those who falsely believe that they have bad breath.