The newborn’s old tongue may be a normal physiological phenomenon, such as sensing the outside world, salivary gland secretion, etc., but it may also be a pathological phenomenon, such as oral diseases, hypothyroidism and so on. 1. Physiological phenomenon: newborns usually explore the surrounding things and perceive the outside world by sticking out their tongues or sucking, and the swallowing function of newborns is not well developed, so when there is too much saliva in the mouth, they cannot swallow the excess saliva in the mouth, which can also lead to the phenomenon of sticking out the tongue of newborns, which is a normal phenomenon. 2. Pathological phenomenon: if the newborn suffers from oral diseases, such as oral herpes or oral ulcers, can also appear the phenomenon of tongue. In addition, if the newborn suffers from congenital hypothyroidism, it will lead to the child’s tongue body hypertrophy, may also appear the phenomenon of tongue. There may be other reasons for newborns to spit out their tongues, so it is recommended to go to the hospital in time, complete the examination to clarify the cause of the disease, and then give targeted treatment or therapy under the guidance of the doctor.