Possible causes of urine protein (+): 1. Kidney disease, such as glomerulonephritis or nephrotic syndrome, can appear increased protein filtration from the glomerulus, increased protein content in the urine, usually accompanied by abnormal kidney function, accompanied by swelling of the limbs, face or abnormal changes in urine volume, further examination of kidney function and urine protein quantification is needed to confirm the diagnosis. 2. Urine protein (+), along with elevated bacteria and leukocytes, some enzymes or some trace protein leakage in the urine after infection. This can occur when the protein (+), usually quantitative detection of urine protein less than 2g, and more often accompanied by urinary tract irritation symptoms, such as urinary frequency, urinary urgency, etc. 3, renal tubular disease, when the occurrence of tubular-related diseases, such as interstitial nephritis or renal tubular acidosis, etc., can appear to reduce the reabsorption of protein by the renal tubules. At this time, urinary heterogeneous protein (+) can appear, carry out 24-hour urine protein quantification less than 2g, generally not accompanied by damage to kidney function, after treatment can achieve complete cure.