Phlegm-like sound in the nasal cavity of infants may be caused by physiological reasons, or may be caused by upper respiratory tract infections, adenoid hypertrophy and other diseases. 1. Physiological reasons: the infant’s nasopharyngeal function is not well developed, more saliva due to not swallowing, may lead to gas and saliva mixed, thus appearing phlegm like sound, usually no other abnormalities, with the growth of age, will slowly ease, and then disappear, no special treatment, pay attention to adjust the sleeping position. 2. Upper respiratory tract infection: when the baby appeared upper respiratory tract infection, due to inflammation caused by nasal secretion for increased, will lead to the emergence of this symptom, if there is a bacterial infection, you can use cefixime and other drugs for anti-infective treatment, and with the use of saline on the nasal cavity to clean to improve the symptoms. In addition, the sound of phlegm in the infant’s nasal cavity may also be caused by adenoid hypertrophy, which should be actively treated for the cause of the disease. Parents are advised to bring their infants to the doctor for a clear diagnosis, and follow the doctor’s instructions to carry out targeted treatment, so as not to miss the opportunity for treatment.