The kidney is a very important organ in the human body, each person has two kidneys, each kidney is the size of a fist, from a medical point of view, each kidney has about one to two million kidney units, the total role of these kidney units is the human body functional kidney, the most important is to produce urine, the body’s metabolic waste through the urine out of the body, including protein and other metabolic products. Similarly, the kidneys, through the production of urine, also act as the inner balance of the body, the balance of water, sodium and electrolytes, and also regulate blood pressure. The renal tubules in the kidneys are responsible for the absorption of essential substances in the body, such as proteins, sugars, amino acids, uric acid, etc. The kidneys also have endocrine functions, secreting renin, which regulates blood pressure and the physiological functions of the body through the endogenous system of renin-angiotensin, and also secretes erythropoietin, for example, sometimes Chinese medicine will say that the kidneys are related to bone and can regulate the balance of calcium and phosphorus metabolism, which can also produce erythropoietin, like bone marrow hematopoiesis, which is actually related to the kidneys. The kidneys secrete erythropoietin, which causes the bone marrow to produce hematopoiesis. The kidneys are closely related to the body and have very important physiological functions and roles.