What causes nitrites in urine?

UTI: Nitrite is a marker on the dipstick that can indicated a uti. Many of the bacteria that cause a UTI create nitrite in the urinary tract and the specific reagent on the dipstick will show its presence.

Nitrites: Presence of nitrites in urine, as opposed to nitrates, is usually a sign of a urinary tract infection by gram negative bacteria- commonly E Coli. Normal urine contains nitrates,however.