The following conditions should be noted when a 3-year-old baby is sweating in bed every night: 1. excessive sweating due to high ambient indoor temperature, which will disappear after improving the ambient temperature, and the physical and mental state are good. 2. vitamin D deficiency, poor calcium absorption, will sweat a lot, apply vitamin D and calcium to children. 3. endocrine diseases, such as the presence of hyperthyroidism, there will be excessive sweating and recent If you feel that your temperament has changed, you need to go to the hospital for examination and, if necessary, thyroid ultrasound and thyroid function tests. 4. Infectious diseases, such as tuberculosis, may increase sweating at night during the active stage, and you may have poor mental health and weakness on weekdays, with or without coughing, so you need to go to the hospital for tuberculin test, X-ray chest X-ray and other related examinations.