Urine protein with three plus signs is not necessarily nephritis. Urine protein can be seen in chronic glomerulonephritis, acute glomerulonephritis and other kidney diseases, but also in urinary tract infections. In addition to urinary tract infection, it can also be manifested as urine protein, urine occult blood and positive urine leukocytes. Clinically, there can be frequency, urgency, painful urination or chills, fever, lower abdominal pain and pain in the unilateral or bilateral kidney area and other uncomfortable symptoms, which are better for differential diagnosis. In addition to urinary tract infection, urine protein can also be seen in certain systemic diseases, such as multiple myeloma, diabetes mellitus, systemic lupus erythematosus, etc., which can lead to damage of the kidney and thus produce urine protein.