Urine microalbumin creatinine ratio, a test used to detect a small amount of protein in urine, or ACR for short, is currently used to screen for microproteinuria in diabetic nephropathy, and its accuracy is higher than that of urinary routine, which can detect patients with small amount of proteinuria that cannot be detected by urinary routine examination. In normal people, the creatinine ratio of urine microalbumin is less than 30 mg/g. If the ratio is between 30 and 300 mg/g, it is considered microalbuminuria, and if it is greater than 300 mg/g, it is considered massive proteinuria. The test should be done three times with morning urine. After the first time the ACR ratio is found to be elevated, the test should be repeated twice in three months and six months later.