Weak legs and sweating may be caused by kidney yin deficiency, kidney yang deficiency, and qi and yin deficiency. 1. Kidney yin deficiency: When kidney yin is deficient, clinical symptoms may include soreness of the waist and knees, weakness of the legs, dizziness, insomnia, heart-heat (heat in the hearts of the hands and feet, and self-consciousness of the heart and chest), hot flashes and night sweating (abnormal sweating after going to sleep, but sweating stops after waking up), and emaciation. 2. Kidney yang deficiency: Kidney yang deficiency is usually related to age, prolonged illness, over-exertion of labor and fear. Patients will experience symptoms such as prolonged diarrhea, fatigue (mental exhaustion, physical weakness), leg weakness, spontaneous sweating (involuntary sweating during the daytime, aggravated by sweating with a little movement), swelling, dizziness, etc. Male patients will also be accompanied by impotence and premature ejaculation, and women will be accompanied by infertility with uterine cold and other manifestations. 3. Deficiency of qi and yin: patients with deficiency of qi and yin will have symptoms such as dry throat, dry mouth, aggravation of sweating after activities, fatigue, weakness of legs, shortness of breath, pale face, constipation, little cracks in the fur of the tongue, and weak and feeble pulse. When the patient has the symptom of soft legs and sweating, it is recommended to clarify the cause of the disease under TCM diagnosis before treatment.