Bad breath in smokers is caused by the tobacco itself—the lungs retain a measure of the tobacco smoke for a while after the cigarette has been extinguished and these chemicals remain in the mouth, making a greater case for halitosis.
The most common cause of chronic severe bad breath is a dental infection. We do not mean a simple overgrowth of oral bacteria due to a buildup of plaque. That is what we discussed in the previous section. We mean an active dental disease, like decay (cavities) or gum disease.

The only way to prevent the bad breath caused by these habits is to quit the habit. We don’t like telling people what to do, but considering all of the serious health consequences of smoking, tobacco and vaping, we feel comfortable telling you to just quit. Not only will it improve your breath, it will protect your overall health.
Bad breath in babies or young children may be a sign of infection or undiagnosed medical problems. Consult the child's doctor or dentist if an infant or young child has bad breath. A complete medical and dental history should be taken. The patient will be asked about their bad breath problem, dietary habits, tobacco use, medications, medical conditions, and family history.A dentist will examine the patient's mouth. X-rays may be taken, and periodontal charting may be done to determine if the odor is due to gum disease.