A routine urine test has an item called nitrite, which is normally negative for nitrite. If the test is negative, it is normal and does not require treatment. Nitrite can be reduced to positive in the presence of enterobacterial infections in the urine, such as Escherichia coli and Klebsiella pneumoniae, and may be reduced to positive in the presence of such bacterial infections. If there is no infection with enterobacteria, nitrite is not considered to be reduced to positive, and the result is usually negative. The urine routine test contains a variety of tests such as white blood cells, red blood cells, etc., and is combined with other tests to determine whether the urine routine is normal or abnormal. Based on the specific positive or negative results, it is possible to determine whether there is a relevant disease in the urinary system.