The main functions of the kidneys are to store essence, water, and Qi, and to produce marrow in the bones to fill the brain. The kidneys are open to the ears and the two yin, and they are in close proximity to the bladder. Therefore, the pathologies of the kidneys are mostly manifested in the failure of the kidney essence storage, abnormal metabolism of water and fluid, abnormal growth, development, reproduction and premature aging, as well as the failure of the qi intake. The kidneys contain yin and yang, which should only be fixed and not depleted, and their pathology is mostly deficiency. The basic symptoms of kidney disease are soreness and weakness of the waist and knees, tinnitus and deafness, etc. Kidney yin deficiency is due to insufficient endowment or overwork. The deficiency is caused by the depletion of kidney yin through the use of warm, dry and yin-robbing drugs. Clinical manifestations include dizziness, tinnitus and deafness, loose teeth, insomnia and spermatorrhea, dryness of the oropharynx, feverishness of the five hearts, night sweating, soreness of the waist and knees. The tongue is red with little essence and the pulse is fine. Kidney Yin deficiency is observed in the spirit: dryness, heat and restlessness, easy to fire; in the face: red cheekbones, face is vivid; in the tongue: red tongue, thin tongue shape, little, bookish tongue coating, in the cold and heat: fear of heat, hot sweat, five hearts are bothered by heat; in the painful part of the disease: soreness of the waist. Clinically, kidney-yin deficiency and lung-yin deficiency exist with each other, resulting in deficiency heat, night sweating, and dry cough in patients. The liver and kidney are of the same origin; kidney essence and liver blood feed each other; kidney yin deficiency leads to hyperactivity of liver yang and water does not contain wood. Relatively speaking, women and young and middle-aged people are more prone to Kidney-Yin deficiency.