Infant drooling is a frequent phenomenon, and in most cases it is physiological, that is, normal. Causes of infant drooling are common in the following aspects, most babies in life are 3-4 months after the start of drooling, this age baby salivary glands began to develop, saliva secretion increased, and the volume of the mouth is relatively small and shallow, the baby will not take the initiative to swallow saliva, so there will be drooling phenomenon, as the baby grows up this phenomenon will gradually ease, this is a normal This is a normal physiological phenomenon. Of course, if the child suddenly appears drooling, pay attention to see if the child has a mouth ulcer, stomatitis, teething and other problems, in this case because of local discomfort, the baby can appear bad food phenomenon. If the drooling is accompanied by fever and a runny nose, the child has laryngitis or tonsillitis. If the baby has chicken pox or hand, foot and mouth disease, chicken pox can cause drooling if it grows on the mucous membrane of the mouth and hand, foot and mouth disease when the herpes in the throat is obvious. If the drooling is accompanied by abnormal behavior, it is important to pay attention to whether the baby has facial nerve palsy, mental retardation, or sequelae of meningitis. Infant drooling can be a normal physiological phenomenon, but it can also be a manifestation of mouth ulcers, hand, foot and mouth disease or even cerebral palsy.