The symptoms of bad breath in infants are generally two main factors, one is the presence of oral diseases in the mouth, and then the digestive system problems. 1, oral disease: generally infants in about six months will have milk teeth. The hygiene of milk teeth must be kept well, and the oral hygiene of children must be kept well, so that the caries of milk teeth can be prevented. Because the infant’s self-consciousness is relatively poor, so parents must pay attention to the child’s oral problems. Give your child water and brush teeth after milk and food every day. It must be a good habit, otherwise, the teeth will be slowly decayed. Once there is tooth decay in the mouth, it will cause bad breath. Therefore, we must pay attention to the oral hygiene of infants and make good habits of brushing teeth. 2, digestive system diseases: digestive system problems are mainly related to indigestion. In this case, you can eat some probiotics. There is also a specific examination to see if there are other diseases in the baby’s digestive system. To make treatment according to the examination. Bad breath in infants must be taken seriously by parents, who must pay attention to oral health and eating habits. It is also important to check if the child has any nose disorders, which can also cause bad breath.