Positive urine protein is divided into physiological proteinuria and pathological proteinuria, physiological proteinuria has the following characteristics: 1, the urine protein content is small, usually not more than 500mg in 24 hours; 2, the urine protein is a small molecule protein, which can be determined by chemical testing; 3, there are clear triggers, such as strenuous exercise, fever, or a large number of high-protein diets, etc., which can cause physiological proteinuria, and it can be converted to negative proteinuria after the removal of the above triggers; 4, there are no other renal disease manifestations such as high blood pressure, hematuria, edema and so on.