All information on Nitrite

At a glance

Nitrite is a nitrogen compound formed from nitrate in bacterial urinary tract infections.

If nitrite is found in the urine, this is a reliable indication of a significant increase in bacteria, which in turn indicates a urinary tract infection, such as urinary bladder inflammation (cystitis) or kidney pelvic inflammation (pyelonephritis).

However, the Nitrite indicator is not a reliable whistleblower for the presence of an infection.

Because if you don’t find nitrite in the urine, this does not exclude a urinary tract infection.

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And in about half of all cases of clear urinary tract infection, no nitrite is found in the urine, as, for example, not all bacterial species form nitrite.

Or the urine wasn’t in the bladder long enough and the bacteria just didn’t have enough time to form nitrite.

So the urine should remain in the bladder for more than four hours to obtain a reliable test result. For this reason, always the morning urine should be examined for a meaningful examination result. If the urine is heavily diluted due to large amounts of drinking, the nitrite test can also be negative, even though there is a urinary tract infection.

If there are extremely many bacteria in the urine, the nitrite can be further broken down by the bacteria and is then no longer detectable. If there is not enough nitrate in the urine from the beginning, any bacteria that may exist cannot form a nitrite.

With one-sided diet, malnutrition, artificial diet or breast milk nutrition of the infant, there may be too little nitrate in the urine, so that the problem of nitrite detection persists. Antibiotics can also interfere with nitrite formation.

All these points show that if there is a suspicion of a urinary tract infection, the test for nitrite in the urine is far from sufficient, but that further examinations are in any case necessary.


  • Hübl, W.: Nitrit im Harn – Übersicht, URL:, Retrieved 18.06.2019
  • Lahnsteiner, E. et al. (2004): Harnanalyse – praktisch zusammengefasst, 2. Auflage
  • Machetanz, L. (2017): Nitrit, URL:, Retrieved 18.06.2019
  • Roche Diagnostics Deutschland GmbH (2014): Kompendium der Urinanalyse. Urinteststreifen und Mikroskopie, 1-196
Status of information: 2022