4-year-old baby night sleep sweating may be related to physiological factors such as high environmental temperature, etc., may also be related to pathological factors such as vitamin D deficiency rickets, hypoglycemia and so on. 1. Physiological factors: due to the 4-year-old baby’s body metabolism or in the higher temperature of the sleep environment, may lead to the emergence of the night sleep sweating, do not need to worry too much. 2. Pathologic factors: (1) Vitamin D deficiency rickets: mainly caused by vitamin D deficiency, insufficient sunlight, excessive growth rate, resulting in abnormal calcium and phosphorus metabolism, often showing irritability, excessive sweating, easy to scare, etc., which may lead to the emergence of nighttime sleep sweating in 4-year-old babies. (2) hypoglycemia: mainly due to insufficient intake of sugar, improper diet, excessive physical exertion, etc., often showing fatigue, anxiety, sweating, tremor, etc., which may lead to the appearance of 4-year-old baby night sleep sweating. Therefore, if a 4-year-old baby sleep sweating at night, it is recommended that attention should be paid to observe whether the symptoms have improved, if no improvement or aggravation is recommended to seek early medical attention.