What causes men to have bad breath?

Male halitosis may be caused by the following factors: 1. Bad hygiene habits, such as poor oral hygiene habits, if food residues in the teeth do not rinse in time, may cause halitosis. 2. Eating some special foods, such as garlic, garlic sprouts and onions, if not cleaned in time after eating these foods, will cause halitosis. Smokers are prone to bad breath, some diseases, such as uremia, lung abscess, constipation, may show bad breath, there are some dental diseases, such as untreated tooth decay, periodontitis, tartar, and chronic gastritis, atrophic gastritis, severe indigestion, etc., may produce bad breath.