Young children’s bad breath may be physiological factors, but also may be the manifestation of certain diseases, such as oral inflammation, dyspepsia, etc., should be timely consultation to identify the cause of the disease. 1. Physiological factors: If a young child consumes onions, leeks, stinky tofu and other irritating odors caused by food temporary bad breath, can be relieved by avoiding these foods. 2. Pathologic factors: (1) oral inflammation: many young children with oral inflammation, especially with gingivitis and dental caries, are also prone to bad breath. (2) indigestion: many young children’s gastrointestinal function is not very good, usually snacks eat more, or eat unclean things, the burden of the gastrointestinal tract will be increased, so it is easy to appear gastrointestinal system diseases, and even gastrointestinal disorders, indigestion, etc., in this case, young children are also prone to bad breath. In addition to the above factors, other factors can not be ruled out. It is recommended that if you exclude physiological reasons, you should consult a doctor in time to clarify the cause of the disease and give targeted treatment.