Smoking bad breath may be caused by oral hygiene problems, periodontitis and other reasons. 1. Oral hygiene problems: usually may be due to patients do not brush their teeth for a long time or not timely clean up the oral cavity after smoking, resulting in bad breath, smoking affects the patient’s blood circulation, resulting in a reduction in local immunity, which leads to oral odor and other diseases. It is recommended that patients clean up the residue inside the mouth and gargle in time in their daily life. 2. Periodontitis: due to the periodontal tissues are damaged, the force to support the teeth will be loosened, shifted and other symptoms, resulting in residues stored in the teeth gap, which leads to bad breath. Patients usually need to eat less greasy, irritating food. Smoking bad breath may also be caused by stomach disease, indigestion and other reasons, it is recommended that patients try to quit smoking to prevent bad breath aggravation, and at the same time to develop good habits, try to light food. At the same time, go to the hospital for examination, under the guidance of the doctor reasonable treatment.