Bad breath alone cannot determine H. pylori infection. Because there are many causes of bad breath, including oral diseases and gastritis, and H. pylori is only more closely related to gastrointestinal diseases, it cannot be clearly determined. H. pylori usually exists in the human stomach, and the infection is likely to cause gastritis and peptic ulcer, which affects the health of the stomach and in turn leads to bad breath. In addition to bad breath caused by H. pylori, the presence of untreated dental caries, gingivitis, periodontitis in the mouth, or non-H. pylori-induced diseases such as purulent tonsillitis and rhinitis can also lead to bad breath. If patients want to know if they are infected with H. pylori, they can go to a hospital gastroenterology department for a C13 or C14 breath test, which is a relatively simple test and does not cause discomfort. Regardless of the cause of bad breath, patients need to pay attention to their oral hygiene, develop good brushing habits, try to brush their teeth once in the morning and once in the evening, if possible, you can use warm water or warm salt water to rinse your mouth after meals.