The presence of leukocyte esterase in the urine, if positive, is most often seen in urinary tract infections, such as the presence of pyelonephritis and urethritis. Because leukocyte lipase, which is present only within the granulocytes, increases the number of granulocytes when an infection occurs in the urinary tract. It is also seen in some tuberculous diseases of the urinary tract, or in the case of kidney transplant rejection, which also results in a positive leukocyte esterase. It is usually accompanied by an increase in the number of leukocytes in the urine or an increase in the number of bacteria, and may also be accompanied by a positive urine reaction for nitrite, as well as symptoms of infectious irritation such as frequent urination, urgency, and painful urination. It is necessary to perform urine culture and anti-infection treatment. According to the results of culture, the specific causative organism will be clarified, sensitive antibiotics will be selected, and regular anti-infection treatment will be carried out to cure the disease.