How do you test for nitrites in urine?
A urinalysis, also called a urine test, can detect the presence of nitrites in the urine. Normal urine contains chemicals called nitrates. If bacteria enter the urinary tract, nitrates can turn into different, similarly named chemicals called nitrites. Nitrites in urine may be a sign of a urinary tract infection (UTI).
UTIs are one of the most common types of infections, especially in women. Fortunately, most UTIs are not serious and are usually treated with antibiotics. It's important to see your health care provider if you have symptoms of a UTI so you can start treatment right away.
Other names: urine test, urine analysis, microscopic urine analysis, microscopic examination of urine, UA
What is it used for?
A urinalysis, which includes a test for nitrites in urine, may be part of a regular exam. It may also be used to check for a UTI.
Why do I need a nitrites in urine test?
Your health care provider may have ordered a urinalysis as part of a routine checkup or if you have symptoms of a UTI. Symptoms of a UTI may include:
- Frequent urge to urinate, but little urine comes out
- Painful urination
- Dark, cloudy, or reddish colored urine
- Bad smelling urine
- Weakness and fatigue, particularly in older women and men
What happens during a nitrites in urine test?
Your health care provider will need to collect a sample of your urine. During your office visit, you will receive a container to collect the urine and special instructions to make sure that the sample is sterile. These instructions are often called the "clean catch method." The clean catch method includes the following steps:
- Wash your hands.
- Clean your genital area with a cleansing pad given to you by your provider. Men should wipe the tip of their penis. Women should open their labia and clean from front to back.
- Start to urinate into the toilet.
- Move the collection container under your urine stream.
- Collect at least an ounce or two of urine into the container, which should have markings to indicate the amounts.
- Finish urinating into the toilet.
- Return the sample container as instructed by your health care provider
Will I need to do anything to prepare for the test?
You don't need any special preparations to test for nitrites in urine. If your health care provider has ordered other urine or blood tests, you may need to fast (not eat or drink) for several hours before the test. Your health care provider will let you know if there are any special instructions to follow.
Are there any risks to the test?
There is no known risk to having a urinalysis or a nitrites in urine test.
What do the results mean?
If there are nitrites in your urine, it may mean that you have a UTI. However, even if no nitrites are found, you still may have an infection, because bacteria don't always change nitrates into nitrites. If you have symptoms of a UTI, your health care provider will also look at other results of your urinalysis, especially the white blood cell count. A high white blood cell count in urine is another possible sign of an infection. To learn what your results mean, talk to your health care provider.
Is there anything else I need to know about a nitrites in urine test?
If a urinalysis is part of your regular checkup, your urine will be tested for a variety of substances along with nitrites. These include red and white blood cells, proteins, acid and sugar levels, cell fragments, and crystals in your urine.
- Hinkle J, Cheever K. Brunner & Suddarth's Handbook of Laboratory and Diagnostic Tests. 2nd Ed, Kindle. Philadelphia: Wolters Kluwer Health, Lippincott Williams & Wilkins; c2014. Urinalysis; p. 508–9.
- James G, Paul K, Fuller J. Urinary Nitrite and Urinary-tract Infection. American Journal of Clinical Pathology [Internet]. 1978 Oct [cited 2017 Mar 18]; 70(4): 671–8. Available from: http://ajcp.oxfordjournals.org/content/ajcpath/70/4/671.full.pdf
- Lab Tests Online [Internet]. American Association for Clinical Chemistry; c2001–2017. Urinalysis: The Test; [updated 2016 May 25; cited 2017 Mar 18]; [about 4 screens]. Available from: https://labtestsonline.org/understanding/analytes/urinalysis/tab/test
- Lab Tests Online [Internet]. American Association for Clinical Chemistry; c2001–2017. Urinalysis: Three Types of Examinations; [cited 2017 Mar 18]; [about 5 screens]. Available from: https://labtestsonline.org/understanding/analytes/urinalysis/ui-exams/start/1#nitrite
- Mayo Clinic [Internet]. Mayo Foundation for Medical Education and Research; c1998–2017. Urinalysis: How you prepare; 2016 Oct 19 [cited 2017 Mar 18]; [about 4 screens]. Available from: http://www.mayoclinic.org/tests-procedures/urinalysis/details/how-you-prepare/ppc-20255388
- Mayo Clinic [Internet]. Mayo Foundation for Medical Education and Research; c1998–2017. Urinalysis: What you can expect; 2016 Oct 19 [cited 2017 Mar 18]; [about 5 screens]. Available from: http://www.mayoclinic.org/tests-procedures/urinalysis/details/what-you-can-expect/rec-20255393
- Merck Manual Consumer Version [Internet]. Kenilworth (NJ): Merck & Co., Inc.; c2017. Urinalysis; [cited 2017 Mar 18]; [about 2 screens]. Available from: https://www.merckmanuals.com/home/kidney-and-urinary-tract-disorders/diagnosis-of-kidney-and-urinary-tract-disorders/urinalysis
- National Institute of Diabetes and Digestive and Kidney Diseases [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Urinary Tract Infections (UTIs); 2012 May [cited 2017 Mar 18]; [about 3 screens]. Available from: https://www.niddk.nih.gov/health-information/urologic-diseases/urinary-tract-infections-utis
- Saint Francis Health System [Internet]. Tulsa (OK): Saint Francis Health System; c2016. Patient Information: Collecting a Clean Catch Urine Sample; [cited 2017 Apr 13]; [about 3 screens]. Available from: https://www.saintfrancis.com/lab/Documents/Collecting%20a%20Clean%20Catch%20Urine.pdf
- The Johns Hopkins Lupus Center [Internet]. Johns Hopkins Medicine; c2017. Urinalysis; [cited 2017 Mar 18]; [about 3 screens]. Available from: https://www.hopkinslupus.org/lupus-tests/screening-laboratory-tests/urinalysis/
- University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2017. Health Encyclopedia: Microscopic Urinalysis; [cited 2017 Mar 18]; [about 2 screens]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&contentid;=urinanalysis_microscopic_exam
- University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2017. Health Encyclopedia: Urinary Tract Infections (UTIs); [cited 2017 Mar 18]; [about 2 screens]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=85&contentid;=P01497