The reason why girls sweat in bed is usually related to the sleeping environment, some diseases and so on. 1. Sleep environment: girls sleep when the environment temperature is suitable for the body, generally do not sweat, such as the phenomenon of frequent sweating, it should be a bad sleeping environment, such as room temperature is too high, room air circulation, room hygiene quality is poor or sleeping bedding is too thick, will lead to the phenomenon of sleeping sweating. 2. Part of the disease: part of the body disease causes can also lead to sleep sweating, such as thyroid, hypertension, diabetes or malignant tumors, etc., have led to the phenomenon of sleep sweating, such as the exclusion of environmental causes, it is recommended to go to the hospital to do a systematic examination to confirm the cause of sweating. In addition, to avoid sweating can be changed by sleeping clothes, bedding, keep the skin dry. Before going to bed, pay attention to the emotional calm not fluctuation ups and downs, affecting the quality of sleep.