The renal function tests of different hospitals are slightly different. The renal function tests generally include blood creatinine, blood urea nitrogen, blood uric acid and cystatin C, and their clinical significance is slightly different. 1. Blood creatinine: It is a nitrogenous metabolite of human body, which is mainly excreted through kidneys. The level of blood creatinine ranges from 53 to 106 μmol/L in adult male and 44 to 97 μmol/L in adult female, and it is one of the most commonly used tools to assess the glomerular filtration rate in clinical practice. 2. Blood urea nitrogen: it is the metabolite of ammonia in the body, which is mainly excreted by the kidneys. The normal range for adults is 3.2-7.1 mmol/L, which can also reflect the glomerular filtration function, and it is usually elevated at the same time with the blood creatinine level. 3. Blood uric acid: it is the metabolism product of purine food, normal range: 150~416μmol/L for men, 89~357μmol/L for women; elevated uric acid causes hyperuricemia, which causes a series of metabolism-related diseases. 4.Cystatin C: Normal range 0.6~2.5mg/L, it can react more sensitively to early glomerular filtration function. If any of the four indicators of nephropathy are abnormal, it is recommended to consult the hospital in time, standardize the treatment under the guidance of doctor if necessary, and have regular review.