Many parents go to the hospital with the complaint of phlegm sound in the throat of newborns. The reasons for phlegm in newborns are: 1. To distinguish when the phlegm sound is, for example, the child can clearly hear the sound of phlegm in the throat within half an hour after eating milk, that is the incomplete function of the milk stain in the pharyngeal tract after swallowing, so many children will show the performance of phlegm after eating milk; 2. The performance of phlegm in the larynx of newborns is related to the larynx The poor development of cartilage is also related. If the laryngeal cartilage is not well developed, at the same time he has phlegm in addition to respiratory changes; 3. There are often children with gastroesophageal reflux who have phlegm in the pharynx, regardless of any of these factors, it is necessary to go to the local hospital to consult with the local doctor.