The cause of urinary protein 3+ is related to renal permeability, which may cause aggravation of tubulointerstitial hypoxia, glomerulosclerosis and uremia. 1. The cause of urinary protein 3+: generally because of infection, genetic factors, immunogenetic factors, immune and non-immune response-mediated inflammation and other mechanisms induced by local microcirculation disorders in the kidney, induced renal permeability related to, will lead to the inability to effectively block the overflow of proteinuria, caused by urinary protein. 2. Urine protein 3 + harm: easy to induce renal tubular cell hypoxia, then lead to the occurrence of tubular cell injury; macromolecular substances in the thylakoid membrane area aggregation, easy to induce thylakoid membrane cell damage as well as hyperplasia, caused by glomerulosclerosis; untimely treatment is likely to lead to difficult to be degraded collagen fibrin deposition in the kidneys, induced by the end-stage renal disease. It is recommended that patients with urinary protein 3+ should go to regular hospitals for examination and actively seek regular treatment according to the examination results.