Positive urine nitrite is mostly indicative of the presence of urinary tract infections, especially predominantly Escherichia coli infections. The infection can reduce the nitrate in the urine to nitrite, and then a positive result can occur. Patients are usually accompanied by an increase in the number of white blood cells and bacteria in the urine, as well as symptoms associated with cloudy urine, urinary frequency, and urinary urgency. Positive nitrite results can also be seen in patients with long-term indwelling catheters or indwelling ureteral stent tubes or cystostomy tubes, which can lead to exogenous infections, cloudy urine or infections associated with the tubes around the fistula. When the urine is positive for nitrites, further urine culture testing is required to identify the causative organism and, based on the culture results, perform a drug sensitivity test to select the appropriate antimicrobial agent for anti-infective treatment. If the urine is positive for nitrite, most of the infections are likely to have drug-resistant bacteria, so it is not recommended to use antimicrobials blindly or empirically.