Halitosis, or bad breath, is the smell in the breath that bothers the person and those around them. The cause may be related to oral problems as well as non-oral ones. Periodontal (gingiva diseases) diseases

, dental decays, dental tartars, restorations such as poorly made fillings or prostheses, diseases that cause dry mouth, some drugs, and infectious diseases such as tonsillitis are some of the oral factors in bad breath.

Chronic lung disease and other respiratory system diseases, gastrointestinal (stomach-intestines) system diseases, kidney failure, and some hematological diseases can be listed as the non-oral factors in bad breath. In addition, hunger, poor oral hygiene, intake of some odor-producing foods, alcohol, and smoking may also be factors in bad breath. The most important part in treatment is to reveal and eliminate or prevent the factor causing the odor.