Answer : There are many possible causes for a person to have bad breath. Some of these include dry mouth (xerostomia), tobacco use, acid reflux, and food particles left from infrequent brushing and flossing. Bad breath may be a sign of certain medical disorders. Mouthwashes are generally cosmetic and do not have a long lasting effect. Maintaining good oral health is essential to reducing bad breath. Brush twice a day with fluoride toothpaste to remove food debris and plaque. It is important to brush your tongue, too. Once a day, use floss or an interdental cleaner to clean between teeth.