What it is: A urine nitrite test checks for nitrites in a urine sample, produced when certain bacteria convert urinary nitrates into nitrites, as part of a dipstick urinalysis.
Why it's ordered: Ordered to help screen for a urinary tract infection (UTI), typically alongside leukocyte esterase and urine microscopy, when symptoms like painful or frequent urination are present.
What it detects: A positive nitrite result suggests bacteria capable of this conversion (commonly E. coli) are present in the urinary tract, though not all UTI-causing bacteria produce nitrites, so a negative result doesn't rule out infection.
Collection & prep: A urine sample collected in a clean container, ideally a first-morning or held sample, since nitrites need time to form in the bladder. No special preparation is required.
Results:
Positive – suggests a bacterial urinary tract infection, especially alongside positive leukocyte esterase
Negative – doesn't rule out infection, since some bacteria don't produce nitrites
Possible complications of an untreated UTI: Left untreated, a lower urinary tract infection can spread to the kidneys, causing a more serious infection; a positive nitrite result combined with symptoms usually leads to a urine culture to confirm the bacteria and guide antibiotic choice.
Statements made in the Clinical Manual have not been evaluated by the FDA. The products mentioned are not intended to diagnose, treat, cure or prevent any disease.
