Known as halitosis, bad breath has an unpleasant odor. This odor can strike at times or be persistent, depending on the cause. For many, the millions of bacteria that live in the mouth ; especially on the back of the tongue are the primary causes of bad breath. The mouth’s warm, moist conditions make an ideal environment for these bacteria to grow. Most bad breath is the result of poor oral hygiene.
Some types of bad breath, such as “morning mouth,” are considered to be fairly normal, and they usually are not health concerns. The morning bad breath occurs because the saliva that regularly washes away decaying food and odors during the daytime diminishes at night while you sleep. Your mouth becomes dry, and dead cells adhere to your tongue and to the inside of your cheeks. Bacteria use these cells for food and expel compounds that have a foul odor.