The human kidneys are located on either side of the retroperitoneal spine, approximately from the 12th thoracic vertebra to the 3rd lumbar vertebra. The right kidney is half to one vertebra lower than the left kidney. Its main functions include filtration, reabsorption and excretion, and endocrine functions. Kidney is an integral part of the urinary system, belonging to the extraperitoneal substantial organs, there is one on each side, the upper pole of the left kidney is flat at the lower edge of the 11th thoracic vertebra, and the lower pole is flat at the lower edge of the 2nd lumbar vertebra; the upper pole of the right kidney is flat at the 12th thoracic vertebra, and the lower pole is flat at the 3rd lumbar vertebra, so that the 12th rib is just diagonally across the middle of the back of the left kidney or the upper part of the back of the right kidney. Kidney has the physiological function of excreting metabolites, maintaining water, electrolyte and acid-base balance, and it also has the function of endocrine, which can secrete many hormones and biologically active substances including erythropoietin, renin, prostaglandin and so on. If the patient has discomfort in the kidney area, it is recommended to go to the regular hospital in a timely manner, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment under the guidance of the doctor.