Proteinuria is defined as the amount of protein in the urine exceeding the normal range. It is usually urine protein greater than or equal to 1+ in routine urine examination, 2~3 times in a row within 1 week, or 24-hour urine protein quantification >150mg. If 24-hour urine protein quantification >50mg/kg is massive proteinuria. Classification: 1. Transient proteinuria: i.e., transient proteinuria discharged by normal kidneys, mostly occurs after fever, heart failure, strenuous exercise, cold bath, and generally does not require special treatment. 2, postural proteinuria: proteinuria appears in upright position and disappears after lying down. Laboratory tests are negative for morning urine protein and positive for afternoon urine protein, which generally do not require special treatment. 3, pathological proteinuria: usually persistent proteinuria, caused by various kidney diseases, further examination is needed.