The kidneys are filtering the blood in the body every minute, this is the function of the kidneys, by filtering the blood to filter out the toxins, and then through the kidneys to produce urine to excrete the toxins, usually the blood flow through the kidneys of normal people is 80-120mg/min, the flow is very large. Renal blood flow clearly reflects the kidney function. When evaluating kidney function, many patients will say whether high blood creatinine means bad kidney function, in fact, blood creatinine is only a small molecule toxin inside the body, which can reflect kidney function by measurement, but renal blood flow is the real indicator of kidney function. There is a clinical gold standard for the determination of renal blood flow, which is the isotope nuclide measurement of renal blood flow, and some other clinical indicators can also reflect renal blood flow, such as blood creatinine value, blood urea nitrogen and other clinical indicators, through the regular hospital to test, the detection of renal blood flow often requires radionuclides, and it is not recommended to test many times, but for long-term patients with chronic renal failure, you can regularly go to the hospital to improve this However, for patients with long-term chronic renal failure, this test can be improved regularly in the hospital to assess the function of the kidneys.