Kidney Stone Analysis

What is a kidney stone analysis?

Kidney stones are small, pebble-like substances made from chemicals in your urine. They are formed in the kidneys when high levels of certain substances, such as minerals or salts, get into the urine. A kidney stone analysis is a test that figures out what a kidney stone is made of. There are four main types of kidney stones:

Calcium, the most common type of kidney stone
Uric acid, another common type of kidney stone
Struvite, a less common stone that is caused by urinary tract infections
Cystine, a rare type of stone that tends to run in families

Kidney stones can be as small as a grain of sand or as large as a golf ball. Many stones pass through your body when you urinate. Larger or odd-shaped stones can get stuck inside the urinary tract and may need treatment. While kidney stones rarely cause serious damage, they can be very painful.

If you've had a kidney stone in the past, you are likely to get another one. A kidney stone analysis provides information on what a stone is made of. This can help your health care provider develop a treatment plan to reduce your risk of forming more stones.

Other names: urinary stone analysis, renal calculus analysis

What is it used for?

A kidney stone analysis is used to:

Figure out the chemical makeup of a kidney stone
Help guide a treatment plan to prevent more stones from forming

Why do I need a kidney stone analysis?

You may need a kidney stone analysis if you have symptoms of a kidney stone. These include:

Sharp pains in your abdomen, side, or groin
Back pain
Blood in your urine
Frequent urge to urinate
Pain when urinating
Cloudy or bad-smelling urine
Nausea and vomiting

If you've already passed a kidney stone and you kept it, your health care provider may ask you to bring it in for testing. He or she will give you instructions on how to clean and package the stone.

What happens during a kidney stone analysis?

You will get a kidney stone strainer from your health care provider or from a drug store. A kidney stone strainer is a device made of fine mesh or gauze. It is used to filter your urine. You will also get or be asked to provide a clean container to hold your stone. To collect your stone for testing, do the following:

Filter all your urine through the strainer.
After each time you urinate, check the strainer carefully for particles. Remember that a kidney stone can be very small. It may look like a grain of sand or a tiny piece of gravel.
If you find a stone, put it in the clean container, and let it dry.
DO NOT add any fluid, including urine, to the container.
DO NOT add tape or tissue to the stone.
Return the container to your health care provider or laboratory as instructed.

If your kidney stone is too large to pass, you may need a minor surgical procedure to remove the stone for testing.

Will I need to do anything to prepare for the test?

You don't need any special preparations for a kidney stone analysis.

Are there any risks to the test?

There is no known risk to having a kidney stone analysis.

What do the results mean?

Your results will show what your kidney stone is made of. Once your health care provider has these results, he or she can recommend steps and/or medicines that may prevent you from forming more stones. The recommendations will depend on the chemical makeup of your stone.

If you have questions about your results, talk to your health care provider.

Is there anything else I need to know about a kidney stone analysis?

It's important to filter all your urine through the kidney stone strainer until you find your kidney stone. The stone may pass at any time, day or night.

References

Johns Hopkins Medicine [Internet]. Johns Hopkins Medicine; Health Library: Kidney Stones [cited 2018 Jan 17]; [about 3 screens]. Available from: http://www.hopkinsmedicine.org/healthlibrary/conditions/adult/kidney_and_urinary_system_disorders/kidney_stones_85,p01494
Lab Tests Online [Internet]. Washington D.C.; American Association for Clinical Chemistry; c2001–2018. Kidney Stone Analysis [updated 2018 Jan 15; cited 2018 Jan 17]; [about 3 screens]. Available from: https://labtestsonline.org/tests/kidney-stone-analysis
Mayo Clinic [Internet]. Mayo Foundation for Medical Education and Research; c1998–2018. Kidney stones: Overview; 2017 Oct 31 [cited 2018 Jan 17]; [about 3 screens]. Available from: https://www.mayoclinic.org/diseases-conditions/kidney-stones/symptoms-causes/syc-20355755
Merck Manual Consumer Version [Internet]. Kenilworth (NJ): Merck & Co., Inc.; c2018. Stones in the Urinary Tract [cited 2018 Jan 17]; [about 2 screens]. Available from: http://www.merckmanuals.com/home/kidney-and-urinary-tract-disorders/stones-in-the-urinary-tract/stones-in-the-urinary-tract
National Kidney Foundation [Internet]. New York: National Kidney Foundation Inc., c2017. A to Z Health Guide: Kidney Stones [cited 2018 Jan 17]; [about 3 screens]. Available from: https://www.kidney.org/atoz/content/kidneystones
The University of Chicago [Internet]. University of Chicago Kidney Stone Evaluation and Treatment Program; c2018. Kidney Stone Types [cited 2018 Jan 17]; [about 8 screens]. Available from: https://kidneystones.uchicago.edu/kidney-stone-types
University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2018. Health Encyclopedia: Kidney Stone (Urine) [cited 2018 Jan 17]; [about 2 screens]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&contentid=kidney_stone_urine
UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2018. Kidney Stone Analysis: How to Prepare [updated 2017 May 3; cited 2018 Jan 17]; [about 4 screens]. Available from: https://www.uwhealth.org/health/topic/medicaltest/kidney-stone-analysis/hw7826.html#hw7845
UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2018. Kidney Stone Analysis: Results [updated 2017 May 3; cited 2018 Jan 17]; [about 8 screens]. Available from: https://www.uwhealth.org/health/topic/medicaltest/kidney-stone-analysis/hw7826.html#hw7858
UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2018. Kidney Stone Analysis: Test Overview [updated 2017 May 3; cited 2018 Jan 17]; [about 2 screens]. Available from: https://www.uwhealth.org/health/topic/medicaltest/kidney-stone-analysis/hw7826.html#hw7829
UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2018. Kidney Stone Analysis: Why It is Done [updated 2017 May 3; cited 2018 Jan 17]; [about 3 screens]. Available from: https://www.uwhealth.org/health/topic/medicaltest/kidney-stone-analysis/hw7826.html#hw7840
UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2018. Kidney Stones: Topic Overview [updated 2017 May 3; cited 2018 Jan 17]; [about 2 screens]. Available from: https://www.uwhealth.org/health/topic/major/kidney-stones/hw204795.html#hw204798
Wolters Kluwer [Internet]. UpToDate Inc., c2018. Interpretation of kidney stone composition analysis [updated 2017 Aug 9; cited 2018 Jan 17]. [about 3 screens]. Available from: https://www.uptodate.com/contents/interpretation-of-kidney-stone-composition-analysis

The medical information provided is for informational purposes only, and is not to be used as a substitute for professional medical advice, diagnosis or treatment. Please contact your health care provider with questions you may have regarding medical conditions or the interpretation of test results.

In the event of a medical emergency, call 911 immediately.