Bad breath, also known as halitosis (9 letters) and rale (4 letters), is an unpleasant odor that can come from the mouth. It is caused by bacteria in the mouth, poor oral hygiene, certain foods, dry mouth, or medical conditions. Bad breath can be embarrassing and can affect one's self-confidence. Treatment for bad breath includes brushing and flossing regularly, using a tongue scraper, drinking plenty of water, avoiding certain foods, and using mouthwash.