Purple yam has the effects of generating fluids and benefiting the lungs, nourishing the spleen and stomach, and tonifying the kidneys and consolidating the kidney essence (by tonifying the kidneys). The efficacy of generating fluids and benefiting the lungs is mostly used in the treatment of lung deficiency and coughing, and the regulation of deficiency heat and thirst. It is more suitable for chronic lung diseases such as lung yin deficiency and lung qi deficiency. The effect of tonifying the spleen and nourishing the stomach is used to treat anorexia, nausea, vomiting, abdominal distension, diarrhea, weakness and other conditions caused by weakness of the spleen and stomach. The effect of tonifying the kidney and astringent essence can be used for the treatment of spermatorrhea, leucorrhea and frequent urination caused by kidney deficiency. Purple yam also contains starch, amylase, choline, amino acids, vitamins, trace elements, saponins and other nutrients have a good nutritional value. It is recommended to take it in moderation under the guidance of a doctor.