The urine occult blood (+) is often the result of routine urine tests, generally if the urine inside the centrifuge, the number of red blood cells per high magnification field of view more than three, you can detect the urine occult blood presented (+), if the number of red blood cells more plus more. If there is urinary occult blood (+) common main causes: first, glomerulonephritis, glomerulonephritis patients in addition to urinary occult blood, there will be a combination of urinary protein may be, urinary occult blood is often presented polymorphic red blood cells. Second, urinary tract infections, there may be urinary occult blood, combined with urinary white blood cells. Third, urinary tract stones, often found in the kidney or ureter or bladder during ultrasound or CT. Fourth, tumors of the urinary tract can also appear to have urinary occult blood. Fifth, systemic systemic diseases, such as thrombocytopenic purpura, systemic lupus erythematosus and other diseases can also lead to have urinary occult blood. Sixth, urinary occult blood also has a certain rate of false positives.