Bad breath can be cause by many factors:
-Inefficient oral hygiene can allow bacterial growth on the tongue, gums and teeth. These bacteria ferment the carbohydrate in your diet and cause bad breath.
-Untreated cavities and infected teeth.
-Diet rich in protein can cause excess of sulphurous gases; coffee, alcohol and cigarettes can also give bad breath as well.
-Gastrointestinal problems such acid reflux, indigestion and constipation can play a role in bad breath.
-Dry mouth, due to certain disease or as an adverse effect of medication, can reduce the cleansing effect of saliva, and that can contribute to bad breath.