The oral cavity is a facade, if there is a problem with breath inevitably make people feel uncomfortable in conversation, just like the Rio Olympic Village, the facade is not good, can not help but affect the reputation and evaluation. Local disorders of the oral cavity is the main cause of bad breath, but should not be ignored is that bad breath is often the oral manifestations of some serious systemic diseases, there are some organic disorders can also lead to halitosis. Common causes of bad breath 1, gastrointestinal diseases such as peptic ulcer, chronic gastritis, functional dyspepsia, etc., may be accompanied by bad breath. 2, psychological stress Psychological stress, regular mental tension leads to the body’s nerves in an excited state, salivary gland secretion is reduced, resulting in dry mouth, which is conducive to the growth of anaerobic bacteria, and halitosis. 3, smoking, alcohol and stimulating food smoking, drinking alcohol, coffee and often eat garlic, leeks and other heavy food taste susceptible to halitosis. In addition, long-term constipation will lead to harmful substances in the body can not be discharged in time, absorbed into the blood and cause bad breath and abdominal distension. 4, oral diseases suffering from dental caries, gingivitis, periodontitis, oral mucositis, as well as tooth decay, periodontal disease and other oral diseases, the oral cavity is easy to breed bacteria, resulting in bad breath. Although bad breath is caused by a variety of aspects, but I believe that we do not want to be troubled by bad breath, as the Brazilian Olympic Committee also hopes to show the world a “good” Olympics, through a reasonable and correct method can also be effective in removing bad breath.