Urine protein 2+ means that 1L of urine contains approximately 1-2g of protein. Urine protein 2+ indicates that the renal filtration membrane has been damaged and permeability has increased, resulting in protein in the urine. Urine protein 2+ is clinically defined as moderate amount of proteinuria, and functional proteinuria as well as postural proteinuria have to be excluded before it can be considered pathological proteinuria. Functional proteinuria and postural proteinuria are called transient proteinuria, and the protein characterization is basically between 1+ and plus or minus, and urinary protein 2+ is considered pathological proteinuria. Pathological proteinuria is mainly seen in various glomerular diseases, tubulointerstitial diseases, hereditary nephropathies, renal vascular diseases and other renal diseases. Glomerular diseases are divided into primary glomerular diseases. Primary glomerular diseases include cryptogenic nephritis, acute nephritis, acute nephritis, chronic nephritis, and nephrotic syndrome. Secondary glomerular diseases are clinically common such as allergic purpura, diabetic nephropathy, lupus nephritis, hypertensive nephropathy, gouty nephropathy, etc. Interstitial renal tubular diseases include pyelonephritis, and hereditary nephropathies include Alport syndrome.