Urine microalbumin is only an indicator to assess the kidney function, even if it is normal, it can not exclude kidney disease, it needs to be judged with other indicators such as blood creatinine. Urine microalbumin less than 30mg/L is normal albuminuria, urine microalbumin can be used for early prediction and diagnosis of hypertensive kidney damage, diabetic nephropathy and so on. Patients with hypertensive renal damage, diabetic nephropathy, etc. glomeruli are in a state of high filtration, and albumin filtration increases, resulting in elevated urine microalbumin levels. Abnormal urinary microalbumin is only one of the signals of renal pathology, so even if this indicator is normal, kidney disease cannot be excluded. For example, some patients with nephritis mainly with hematuria as the main symptom, urine microalbumin may be at a normal level. Tests for kidney disease include urine routine, urine erythrocyte microscopy, 24-hour urine protein quantification, early kidney loss, blood biochemistry, renal ultrasound, etc. Normal urine microalbumin alone cannot rule out kidney disease, and it is recommended that the patient go to the hospital for consultation, and under the guidance of specialists to clearly rule out kidney disease.