Bad breath, or bad breath, is an unpleasant odor emanating from the mouth. Don’t ignore the minor problem of bad breath, it can make others disgusted and embarrassed, thus affecting normal interpersonal and emotional communication. In daily life, in fact, everyone can have bad breath, but smart people will eliminate it without a trace. Le Di, Department of Oral Comprehensive, Peking University Stomatological Hospital To make your breath fresh, you must eliminate the root cause of bad breath to do so. Modern medicine believes that bad breath is divided into two categories: physiological and pathological: physiological bad breath includes: 1, dietary odor: tobacco, alcohol, coffee, onions and garlic, milk and other oral residues caused by the mouth, you can chew chewing gum or tea, etc., so that its own unique aroma decomposition out, you can purify your breath. 2, long periods of fasting: will make the stomach gas up, which leads to bad breath, a healthy diet is the fundamental way to prevent such bad breath. Pathological bad breath includes: 1, do not pay attention to oral hygiene: do not carefully brush, do not use dental floss, wear movable dentures do not pay attention to the cleaning of dentures, will make the long-term accumulation of food residues, fermentation and corruption under the action of bacteria to give off bad odor. We should brush our teeth at least once a day in the morning and evening, use dental floss to clean the gap between the teeth before going to bed, and use a toothbrush to lightly brush the tongue to remove the bacteria on the tongue. 2, oral disease: bad breath is caused by oral disease in the majority of cases. Decay, gum inflammation is also prone to corrupt odor. Need to go to the dentist every six months to a year regularly to check the teeth, timely fillings, scaling can eliminate such bad breath. 3, other physical diseases: indigestion, inflammation of the stomach and other digestive tract diseases, purulent bronchitis, lung abscess, nasopharyngeal cavity diseases (such as pharyngitis, purulent maxillary sinusitis, atrophic rhinitis) mouth breathing and other respiratory diseases, diabetes, metal (such as lead, mercury) and organic poisoning and other conditions, these patients will also have abnormal odor in the mouth. This requires early examination and consultation with an internal medicine and ENT physician.