No one expects to wake up in the morning with fresh breath, but what causes morning breath? Bad breath is something that most of us have dealt with. Sometimes the causes are simple and easy to remedy, other times it might require special attention or a change of habits. Regardless of the cause, bad breath can be embarrassing and a potential health concern. The medical term for bad breath is halitosis, and depending on the cause it may be an occasional occurrence or a long-lasting side effect.