Sweating on the back of the neck after the baby falls asleep may be caused by physiological factors, calcium deficiency, tuberculosis and other factors. 1. Physiological factors: when sleeping, the room temperature is too high or the blanket is too thick, it will lead to sweating at the back of the neck, which is a normal physiological phenomenon, without other clinical symptoms. 2. Calcium deficiency: the lack of calcium in the baby’s body more, in the case of more sweaty neck when sleeping, there may also be restless sleep, leg cramps and other abnormalities, which can seriously affect the physical development. 3. Tuberculosis: when the pediatric presence of tuberculosis lesions, such as tuberculosis, will lead to the baby’s neck sweating while sleeping, may also be accompanied by low fever, fatigue, lethargy, loss of appetite and other symptoms. The baby fell asleep after the neck sweating, there may be other reasons, it is recommended to go to the hospital in time to improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.