When doing a urine test, if the white blood cells are four plus, suggesting the possibility of the following diseases: first, urethritis or cystitis. In urethritis, there will be elevated urine leukocytes, accompanied by urinary urgency, urinary pain and urinary frequency, which is a typical symptom of urinary tract infection. Second, kidney inflammation. Inflammation of the kidneys, in addition to positive urine leukocytes, combined with pain in the kidney area. Third, urinary stones, such as kidney stones or ureteral stones, are also prone to cause 4 plus urine leukocytes. Fourthly, gynecological inflammation, such as vaginitis and vulvitis, also tend to cause urinary tract infection at the same time, and then cause urine leukocytes 4 plus.