What causes proteinuria?

The common causes of proteinuria are urinary tract infection, nephritis, nephrotic syndrome, IgA nephropathy, purpura nephritis, etc. The essential cause of these diseases is that due to the damage to kidney function, the increase in glomerular filtration permeability and the weakening of renal tubular reabsorption capacity, the protein in the plasma cannot be reabsorbed back into the blood after filtration, so it leaks into the urine to form proteinuria. The evaluation of proteinuria requires urine routine and 24-hour urine protein quantification for qualitative, semi-quantitative, and full quantitative evaluation, respectively. Very mild proteinuria can be observed regularly. If there is significant proteinuria, it is necessary to go to the nephrology department for consultation. If necessary, a renal biopsy should be performed to confirm the cause.