Halitosis is a foul odor emanating from the mouth or other air-filled cavities such as the nose, sinuses, and pharynx. Most bad breath is caused by oral factors such as bacteria, tartar, periodontal disease, dental caries, and oral dryness. The degree of bad breath is closely related to the presence and thickness of the tongue and the extent of the tongue, and can be caused by a variety of internal and external factors. Determining the cause of bad breath can be clarified by clinical performance. 1, bad breath caused by oral diseases common oral cavity diseases, such as large cavities, serious periodontal disease, deep periodontal pockets, wisdom teeth pericoronitis in the blind pocket will retain a large amount of food residues, anaerobic bacteria and bacterial metabolites, etc. will cause bad breath. The cause of bad breath can be determined after the treatment of the corresponding disease and the symptoms of bad breath are relieved. 2.Bad breath caused by the growth of plaque Once certain types of bacteria breed on the teeth, they will form plaque in the mouth, which needs to be removed by dental professionals. If treatment measures are not taken in time, plaque will not only cause tooth decay and tooth decay, but also produce bad breath. Patients are recommended to take ultrasonic scaling and if the bad breath is removed, it is proved to be caused by dental plaque. 3, bad breath caused by sinus infection If the patient has a sinus infection, the presence of certain specific types of bacteria in the nose, it is also possible to emit foul odor, you can use saline to rinse the nasal cavity, such as bad breath relief, you can determine that bad breath is caused by sinus infection. 4, bad breath caused by tonsil stones If a certain amount of microorganisms and food debris accumulate in the cracks of the tonsils, it is easy to form tonsil stones, stones taste like rotten eggs and can produce bad breath. If a patient finds pus flowing from the tonsils or has calcification in the crypt, bad breath may be caused by tonsil stones, and minor surgery to remove the stones can be considered. 5, bad breath caused by acid reflux When the patient has problems with the stomach, stomach acid and other components of the stomach reflux from the stomach into the esophagus, it can also lead to bad breath, which can be treated by taking antacid drugs. 6, bad breath caused by dietary problems usually have clear dietary triggers, such as patients have eaten garlic and onions and other foods, can be judged as food to cause bad breath, you can avoid eating such food.