Odor refers to the odor emitted from the mouth or other air-filled cavities (such as nose, sinuses and pharynx). Investigation shows that 1%~65% people in the world have suffered from bad breath, which seriously affects people's psychological and social activities. There are generally three reasons for bad breath: the first is because food remains in the mouth and ferments to form putrefaction; The second is inflammation in the mouth, such as periodontitis and gingivitis. The third is what people often say, "stomach heat and stomach fire are flourishing". If you want to get rid of bad breath, you can take analgesic and bactericidal drugs and take comprehensive care of your mouth. Pay great attention to oral hygiene in life, brush your teeth and rinse your mouth carefully every morning, before going to bed and after meals, and gently brush off the tongue coating with a toothbrush or clean towel when necessary. Drinking more fresh tea, such as many natural jasmine herb tea and mint tea, is helpful to relieve bad breath.