Sleep sweating can be categorized into physiological causes and pathological causes. Physiological causes mainly take into account that we have more sweat glands distributed all over the body, and the secretion of sweat glands is governed by the function of plant nerves. While sleeping at night, the function of the vegetative nerve is enhanced, and the secretion of sweat glands is also enhanced, which makes it easy to sweat. Some people may have excessive activities before going to bed or are mentally nervous, which may stimulate the phyto-neural function to be dysfunctional and lead to sweating in bed. In addition, pathologic causes must also be considered if some people have a cold, fever, some inflammatory diseases or tuberculosis and other systemic diseases, may lead to night sweating phenomenon.