Entry physical examination, urine test drink water must pass is not correct, generally speaking, urine test is recommended to retain the first urine in the early morning prevail. If we drink water, the first may dilute the urine, because after drinking a lot of water, the urine will be diluted, the concentration of some components in the urine will drop. For example, if there is protein or red blood cells in the urine, after drinking water, the original protein urine (++) may become (+), and urine occult blood will also change from (++) to (+), but it does not make these components disappear completely and cannot be detected. If there are white blood cells in the urine, drinking more water and relieving urine may facilitate the elimination of bacteria and reduce the inflammatory response. But in short, drinking water is not the key way to solve the problem, it is best to have a problem before the entry, to promptly seek medical attention.