What is the cause of occult blood 2+in urine

The most common cause of occult blood in urine is kidney disease. Occult blood is the hemoglobin released after the red blood cells in urine burst. It is detected by reagents. When the red blood cells in urine are less than 10 per microliter, the urine occult blood is negative. If the number of red blood cells in urine is greater than or equal to 10 per microliter, the occult blood can be detected positive in routine urine test, and qualitative analysis will add 1 to 4. Urinary occult blood is most commonly seen in primary glomerulonephritis, nephrotic syndrome, hypertensive nephropathy, diabetic nephropathy, hepatitis related nephropathy, lupus nephropathy, interstitial nephropathy, as well as kidney and ureteral tumors, stones, urinary system infections, etc. The female may also be positive after menstruation, which is false positive. There is no kidney disease.