Bad breath from the mouth is a common finding, especially in patients with neglected oral hygiene. Halitosis, as this condition is known, is characterized by an unfavorable odor from the oral cavity. Causes are usually associated with retention sites in the dentition, such as broken teeth and dental restorations, missing teeth that help maintain and decay food debris. Dental plaque and tartar also help keep food residue between the teeth, and subsequent disintegration leads to bad breath from the mouth. Hygienic activities like cleaning teeth, interdental sides and tongue are important here.

Bad breath can also be caused by excessive consumption of certain foods and spices, as well as coffee, alcohol and tobacco. Diseases of the gastrointestinal tract, lungs and kidneys could also cause unpleasant breath of the mouth.