Male bad breath may be caused by the following factors: 1, poor hygiene habits: such as poor oral hygiene habits, if the teeth crevice residual food, do not rinse in a timely manner, may lead to bad breath. 2, eaten food: if some of the food eaten after not rinsing in a timely manner, will lead to the appearance of bad breath, such as garlic, onions, garlic cloves, onions, if these foods after eating without timely oral treatment, will lead to the appearance of bad breath. 3, Smoking: smokers are prone to halitosis, which is annoying. 4, disease caused by: such as the emergence of uremia, lung abscess, constipation, may appear bad breath. 5, there are dental diseases: such as untreated tooth decay, periodontitis, tartar, and chronic sinusitis, atrophic gastritis, severe indigestion, may produce bad breath. 6, Helicobacter pylori infection; can also lead to bad breath, the above is the cause of bad breath in men.