One of the tests in the urine routine is urine occult blood, urine occult blood test is to determine whether there is an increase in red blood cells in the urine. Under normal circumstances after centrifugation of the urine inside the red blood cells, less than three per high power microscope field of view is a normal phenomenon, if more than three or more is known as a positive urine occult blood test. If the number of red blood cells reaches ten per high magnification field of view, it is called urinary occult blood (+), if it is twenty, it is called urinary occult blood (++), and if it is thirty or more, it is called urinary occult blood (++++). Positive urinary occult blood is commonly caused by urinary tract infections, urinary stones, or patients with urinary tract tumors, but also seen in patients with glomerulonephritis.