Four-month-old babies spitting out their tongues may be caused by physiological factors such as hunger and being in the micturition period, or it may be caused by pathological factors such as mouth ulcers and thrush. 1. Normal physiological factors: (1) Hunger: four-month-old babies can’t speak for the time being, and if they are not fed enough, they may send a message by spitting out their tongues when they feel hungry. (2) Micturition: babies at this stage are in the micturition period, and often explore the outside world by spitting out their tongues or licking. 2. Pathologic factors: (1) Mouth ulcers: after the appearance of mouth ulcers, the mucous membrane of the oral skin is irritated, which may lead to the baby’s discomfort and the phenomenon of spitting out the tongue. (2) thrush: clinically, thrush oral mucous membrane rupture and erosion will lead to increased secretion, which will also lead to the baby to spit out the tongue. Four-month-old babies spit out their tongues, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.