Long yam is a food, not a Chinese herb, and does not have medicinal value. The correct one should be yam, which has the effect of benefiting qi and nourishing yin (tonifying qi and nourishing yin fluid), tonifying the spleen, lungs and kidneys, and fixing essence and stopping the band. Long yam is a common food in life, long yam has high nutritional value, moderate consumption of long yam can play a role in nourishing the spleen and stomach, beneficial to the lungs and qi, and has many benefits to the body, but does not have the role of treating diseases. On the other hand, yam is the rhizome of Dioscoreaceae plant Dioscorea spp. and is often used raw or fried in clinical practice. Yam can be used to treat symptoms such as loose stools (thin and unformed feces), lethargy and fatigue due to spleen deficiency, cough and shortness of breath due to lung deficiency, or lumbar and knee soreness (a feeling of weakness and tenderness in the waist and knees) and spermatorrhea due to kidney deficiency. Yam should be used properly under the guidance of a medical professional, and its adverse effects and contraindications are not clear.