There are many indicators of renal function tests, both blood and urine tests. Commonly used tests include blood creatinine, blood urea nitrogen, urine microalbumin test, 24-hour urine protein quantification, serum cystatin C, and ultrasound of the urinary tract. Blood creatinine is the metabolic end product of creatine in muscle tissue. When the renal parenchyma is damaged, the glomerular filtration rate decreases and the blood creatinine concentration increases, so the blood creatinine concentration can be used as an indicator of impaired glomerular filtration rate. Blood urea nitrogen is the end product of protein metabolism. When renal function is impaired, glomerular filtration rate decreases and blood urea nitrogen concentration increases. Urine microalbumin test and 24-hour urine protein quantification can reflect the impairment of glomerular filtration barrier. Serum cystatin C is almost completely taken up and broken down by epithelial cells in the proximal tubule, and is only excreted in trace amounts in the urine, so its level is a sensitive and specific indicator of glomerular filtration function. Urologic ultrasound can provide the size of the kidney, the morphology of the renal envelope, the thickness of the renal parenchyma and the strength of the echoes, which can be helpful for clinical identification of acute and chronic failure. It can also help clinical understanding of the presence of obstructive factors such as stones. Ultrasonography is also sensitive to common renal cystic diseases. If patients need to undergo renal function tests, it is recommended to go to a regular hospital to have the test results prescribed and evaluated by a specialized doctor.