When observing white blood cells, a microscope is often used, which has a low magnification field of view as well as a high magnification field of view. Therefore, the number of white blood cells can be counted under the high magnification field of view, so that the number of white blood cells under the mirror can be judged how many white blood cells. Generally speaking, the counting of white blood cells in the blood routine does not use this method, but will use automatic analyzing instruments. For urine routine can be used in this way, urine routine using high power microscopy test, if the high power microscope under the white blood cells in more than 5, it is called microscopic leukocyturia, suggesting that the urine is likely to have the corresponding infection. But this is not a definitive diagnosis, should be combined with the number of white blood cells, as well as there is no hematuria, bacteria, in addition, there is no frequency of urination, urinary urgency, urinary pain symptoms, to make a comprehensive judgment.