What does high nitrates in urine mean?

Possible infection: Bacteria convert nitrite, a normal byproduct of metabolism excreted into the urine, into nitrate. You should be seen for a urinalysis and possible treatment.

NitrAtes or nitrites: Urinary nitrates (from food additives & dietary protein) are generally considered normal. Nitrites, however, indicate the presence of bacteria that can enzymatically change nitrates into nitrites, which are present in urinary tract infections.