Urine microalbumin less than 30mg/L in healthy adults is within the normal range. Urinary microalbumin can be used for early prediction of hypertensive renal damage, prediction of the development of diabetic nephropathy and early diagnosis. Urinary albumin excretion rate in patients with hypertensive renal damage is significantly higher than normal, positively correlating with increased systolic and diastolic blood pressure, increased intraglomerular pressure, and dysfunctional albumin filtration relationship. It can help to understand the extent of renal damage. The earliest clinical signals in patients with diabetic nephropathy are a persistent increase in urinary albumin excretion and microalbuminuria. Patients with diabetic nephropathy urinary microalbumin <30mg/L for the normoalbuminuria period; when located in the 30 ~ 299mg/L for microalbuminuria period, it is generally believed that at this time the lesion can be recovered after treatment, and urinary microalbumin can be turned into negative. If the patient has abnormal urine microalbumin index, should go to the hospital in a timely manner, under the guidance of a professional physician to clarify the cause of the disease, timely standardized treatment.