The most important cause of yin deficiency is caused by long-term accumulation of time, in the treatment process, the effect is slow, the course of treatment is long, so it seems difficult to cure. The main cause of yin deficiency in the human body is irregular diet, daily stay up late, excessive room labor and other such bad habits. Symptoms of yin deficiency are often manifested as dry mouth and tongue, or accompanied by a dry cough, dry stools, night sweats (sweating abnormally after falling asleep and stopping after waking up), heartburn, insomnia and dreaming, lumbar and knee soreness (the feeling of lumbar and knee soreness and weakness), weakness, and warmth in the hands and feet. Because the symptoms of yin deficiency are pathological changes formed over time, and the treatment process is restricted to mainly replenish yin, the whole process of treatment will be longer and the effect will be slow. The prescription of Six-flavored Di Huang Pill and Sha Shen Maidong Tang can be chosen by professional physicians after identification of the symptoms, and the adverse effects are not yet clear. Patients are advised to consult a doctor in time if they feel unwell, and should not use medication on their own.