Yin deficiency can be caused by both congenital and acquired factors, such as heat illness, sweating, vomiting, blood loss, diarrhea, and also by excessive intercourse, which can lead to kidney yin and kidney essence deficiency. 1. Heat disease injury to the yin: most of the heat disease caused by external infection, but also can be seen in the internal heat, this kind of disease is characterized by easy depletion of fluid, yin deficiency. 2. Yin deficiency caused by sweating, vomiting, blood loss, diarrhea: most of these cases are caused by excessive loss of fluid. 3. Kidney yin deficiency: most of these cases stem from kidney yin deficiency triggered by too much sexual intercourse, prolonged labor, and staying up all night. Yin deficiency belongs to a broad concept, which includes essence and blood deficiency, fluid deficiency, etc., most need to be combined with the patient’s clinical symptoms, tongue, pulse comprehensive judgment. If you have symptoms, you should take medication under the guidance of a professional physician, do not take medication blindly, so as not to delay the condition or produce adverse reactions.