Yam is a Chinese medicine with the effect of tonifying the spleen and lungs (tonifying the spleen and lungs). Yam is the root of Dioscorea spp. in the family of Dioscoreaceae, also known as Dioscorea preocupata, Dioscorea spp., Dioscorea spp., Dioscorea spp., Dioscorea spp., Dioscorea spp. It is sweet in flavor, flat in nature, and belongs to the spleen, lung and kidney meridians. It has the effect of tonifying the spleen and stomach, generating fluids and benefiting the lungs, and tonifying the kidney and astringing the essence. It is mainly used for treating spleen deficiency-induced loss of appetite, loose stools, diarrhea, asthma and cough of the lungs, spermatorrhea of the kidneys, as well as fatigue of the limbs (tiredness and weakness), and internal heat and thirst (internal fever accompanied by excessive eating, drinking, and urination) and other disorders. The drug is contraindicated for people with solid evils and stagnation in the body. If there are any related symptoms, it is recommended to consult a doctor in time and standardize the treatment.