What causes night sweats?

　　Night sweats (also known as “thief sweats”) is a syndrome in Traditional Chinese Medicine (TCM), typically characterized by profuse sweating during sleep, often severe enough to awaken the patient from sleep.

　　There are numerous causes of night sweats. While certain diseases—such as menopausal syndrome—can trigger them, psychological factors and environmental influences may also contribute to varying degrees of night sweats, directly impairing the patient’s quality of sleep. So, what exactly causes night sweats during sleep?

　　What Causes Night Sweats During Sleep?

　　Night sweats primarily stem from Yin deficiency—especially Kidney Yin deficiency. During sleep, Yang Qi enters the interior and forces Yin fluids outward, resulting in spontaneous sweating. In essence, the interaction between Yang and Yin during sleep ultimately drives Yin fluids to the body surface, manifesting as night sweats. Clinically, tuberculosis is a relatively common pathological cause of night sweats; the most effective treatment approach involves traditional Chinese herbal medicine. Pathological night sweats may also result from calcium deficiency, which can be confirmed via serum calcium testing. When engaging in outdoor activities, adjust clothing layers promptly according to weather changes, and dry off promptly after sweating. Daily wear should consist of breathable, 100% cotton garments.

　　When experiencing night sweats, it is essential to identify the underlying cause before deciding whether medication or dietary adjustments are necessary. In the absence of an identifiable primary disease, night sweats are generally attributed in TCM to imbalance between Yin and Yang—specifically, Yin deficiency with hyperactive Fire. Such cases are commonly managed through herbal or dietary therapy aimed at nourishing Yin, clearing Heat, and consolidating the exterior to stop sweating. For instance, Liu Wei Di Huang Wan (Rehmannia Six Formula) effectively clears Heat and restrains sweating. Patients may also undergo pattern differentiation (Bian Zheng) to guide individualized treatment: if Yin deficiency with Fire exuberance is diagnosed, herbs that nourish Yin and arrest sweating may be prescribed. For Yin-deficiency–induced night sweats, herbs with antiperspirant properties—such as Schisandra chinensis (Wu Wei Zi) and floating wheat (Fu Xiao Mai)—may be used. These herbs are best prepared as decoctions rather than teas, offering clinically meaningful therapeutic effects.

　　All medications must be administered under the guidance of a qualified healthcare provider; self-medication is strongly discouraged. We hope this information proves helpful to you.