Why do I sweat excessively while sleeping?

　　In daily life, some individuals experience night sweats—excessive sweating during sleep—a highly abnormal and unhealthy physiological phenomenon. This condition not only impairs sleep quality but also negatively affects one’s mood and overall well-being. So, what causes persistent sweating during sleep?

　　What Causes Persistent Night Sweating?

　　Persistent night sweating is a relatively common clinical symptom, often associated with constitutional weakness or underlying medical conditions. These may include tuberculosis, endocarditis, malignant tumors (e.g., lymphoma), diabetes mellitus, hyperthyroidism, as well as anxiety disorders, depression, and neurosis—all of which can trigger profuse sweating during sleep.

　　If sweating occurs exclusively during sleep and ceases upon waking, this is characteristic of “night sweats” (in Traditional Chinese Medicine, *dao han*). Such night sweats are commonly attributed to yin deficiency with internal heat or damp-heat patterns. Therapeutically, formulas such as Danggui Liuhuang Tang (Rehmannia & Angelica Decoction), Sanren Tang (Three-Kernel Decoction), or Simiao San (Four Marvels Powder) may be prescribed according to the specific pattern.

　　Conversely, if sweating begins immediately upon falling asleep—or even while still awake—and persists throughout sleep, it is classified as “spontaneous sweating” (*zi han*), often indicating qi deficiency or combined qi-yin deficiency, among other possible etiologies. In such cases, treatment options may include Yu Ping Feng Ke Li (Jade Windscreen Granules), Huang Qi Ke Li (Astragalus Granules), or Mu Li San (Oyster Shell Powder), adjusted as needed based on individual presentation.

　　The above outlines the potential causes and TCM perspectives on persistent night sweating. We hope this information proves helpful to you.