Fasting is not required for blood test of renal function, the items included in renal function are creatinine, urea and so on, among which creatinine is the most important, creatinine is a kind of metabolic waste of the human body, which is mainly excreted through the kidneys, and the production and excretion is relatively constant every day, which is affected by the diet and drinking water very little, so the checking of renal function doesn’t require fasting. For the assessment of kidney diseases, in addition to checking renal function, urine routine, renal ultrasound and other items are also needed to know whether there are kidney diseases. Kidney-related diseases commonly include nephritis, nephrotic syndrome, diabetic nephropathy, etc. These diseases need to be treated actively in the early stage to avoid deterioration, and dialysis treatment needs to be started once the kidney disease develops to the final stage, that is, the uremic stage.