Baby gas odor is also known as halitosis, the main consideration and oral cleaning improper, gastrointestinal dysfunction and other factors. 1. Improper oral cleaning: most of the baby’s bad breath is caused by oral local problems, usually the baby’s oral cleaning is not done, resulting in the oral cavity inside the residual food residue produced by the odor; second oral cleaning is not done properly, but also lead to the emergence of plaque, gingivitis, periodontitis and other oral diseases, can also cause halitosis. 2. Gastrointestinal dysfunction: secondly, babies usually eat irregularly, love to snack or eat some unhygienic food, can aggravate the burden on the stomach and intestines, thus causing gastrointestinal diseases, digestive disorders and other phenomena, thus causing bad breath. So the baby out of breath odor should pay attention to timely to the hospital, identify the cause of the timely treatment.