Increased nitrites in the urine are often considered to be a result of urinary tract infections, especially Escherichia coli infections. This is because when E. coli infection is present, nitrates in the urine can be reduced to nitrites, and increased nitrites can be seen on urinalysis. Patients may have a history of urinary frequency, urgency, or pain with urination, along with a significantly higher white blood cell count, requiring urine culture and targeted anti-infective therapy based on the results of the culture. Often also seen in long-term indwelling urinary catheter or indwelling cystostomy tube, ureteral stent tube patients, because of the presence of exogenous pipeline, can cause pipeline-related infections, this can cause Escherichia coli colonization infection, which will lead to increased nitrite in the urine. This situation requires anti-infection treatment or early removal of urinary catheters, cystostomy tubes, ureteral stents in vivo, etc., the urine can gradually return to normal.