Bad breath can have many causes—some normal and others related to health issues. Morning bad breath is common due to reduced saliva during sleep, which normally helps clear bacteria.
Persistent bad breath, however, may signal dental or medical problems. It’s often caused by plaque buildup from poor oral hygiene, gum disease, or cavities. Dry mouth, caused by certain conditions, can also contribute.
Other possible causes include issues with the tonsils, nose, or throat, medical conditions like diabetes or digestive problems, and lifestyle or dietary factors such as smoking, alcohol, or strong-smelling foods.