Sweating on the back can be caused by yin deficiency, but it can also be caused by yang deficiency and qi deficiency. 1. Yin deficiency: deficiency of yin qi and internalization of yang qi, forcing sweat to go out. The main manifestation is night sweating, accompanied by dryness of the mouth and throat, heat in the hands and feet, flushing of the face, irritability and night sweating (sweating abnormally after falling asleep and stopping sweating after waking up), agitation and restlessness, dreaming, and redness of the tongue and other symptoms. 2. Yang deficiency: deficiency of yang qi in the body, the loss of solid control, sweat leakage due to the loss of yang qi external guard, resulting in easy sweating on the back, which may be accompanied by a white face, fatigue, cold (cold body) and cold limbs, pale tongue, white moss, and sluggish and feeble pulse, and other manifestations. 3. Qi deficiency: due to insufficient positive qi in the body, the guard is not solid, the control of sweat is reduced, resulting in easy sweating of the back, accompanied by fatigue, fear of cold, shortness of breath, easy to catch a cold and other symptoms. Patients with back sweating should go to the Department of Traditional Chinese Medicine of regular hospitals in a timely manner, to clarify the cause of the disease, under the guidance of a professional Chinese medicine practitioner to identify the cause and treatment.