Clinically, a 24-hour urine protein quantification of more than 150mg/24h in adults and 300mg/24h in children is diagnosed as proteinuria. Patients often think that urinary foam equals proteinuria, which is inaccurate and must be tested for quantitative proteinuria. However, clinical attention should be paid to exclude pseudoproteinuria. Pseudoproteinuria, as the name implies, is not true proteinuria, but is caused by a positive urine test for protein for some reason. Pseudoproteinuria is usually seen in the following conditions, and if any of these conditions cause proteinuria, an in-depth examination is recommended. Pseudoproteinuria is seen when blood, pus, inflammatory or tumor secretions, menstrual blood, leukorrhea, etc. are mixed in the urine, and the routine qualitative proteinuria test can be positive. After the urine is centrifuged and precipitated or filtered, the qualitative protein test will be significantly reduced or even turned negative; 2. After the urine is left for a long time or cooled, salt crystals can be precipitated, making the urine white and cloudy, which can be easily mistaken for protein urine, but adding warmth or a little acetic acid can turn the cloudy urine clear to help distinguish; 3. The urine is mixed with semen or prostatic fluid, or inflammatory secretions of the lower urinary tract, etc., the urine protein reaction may be positive. In this case, the patient has manifestations of lower urinary tract or prostate disease, and spermatozoa and more flat epithelial cells can be found in the urine sediment to make the distinction; 4. Lymphatic urine, which contains less protein and is not necessarily chylomicronous; the presence of proteinuria can be basically judged as a result of kidney damage by other ultrasound examinations of the kidneys, kidney function tests, and routine urine tests, in addition to excluding other causes such as physiological factors and postural factors the clinical symptoms.