Kidney Stone Analysis
Reviewed
Also called: urinary stone analysis, renal calculus analysis
A kidney stone analysis is a test to find out what a kidney stone is made of.
Specimen: Kidney stone (passed in urine or surgically removed)
Why this test may be ordered
- To determine the chemical composition of a kidney stone you have passed or had removed.
- To help your provider understand why the stone formed and develop a plan to prevent future stones.
Preparation and collection
You don't need any special preparations for a kidney stone analysis.
To collect a kidney stone, you will need a kidney stone strainer to filter your urine and a clean container for your stone. If you find a stone, put it in a clean container with a lid. DO NOT add anything to the container. The stone must be kept dry. DO NOT put tape or tissue on the stone. Return the container to your provider or lab as instructed. If you have pain while the stone is passing, ask your provider about pain medicine.
There is no known risk to having a kidney stone analysis. But passing a kidney stone may cause: Pain depending on the size of the stone, A urinary tract infection, A blocked urinary tract if the stone gets stuck.
Understanding results
Your results will show what your kidney stone is made of. With this information, your provider will be able to recommend steps and/or medicines to help prevent more stones from forming.
- Calcium stone: Calcium is the most common type of stone. Limitation: Calcium stones are the most common type, but they are not caused by eating dairy products. In fact, dairy products can help prevent calcium stones. Next step: Your provider can explain what diet changes can help reduce your risk for stones.
- Uric acid stone: Uric acid is another common type of stone. Limitation: Many things may increase your risk of kidney stones. These can include your diet, some health conditions, and some supplements or medicines. Next step: Your treatment plan will depend on the size, type, and location of the stone.
- Cystine stone: Cystine is an uncommon type of stone. It is caused by cystinuria, a kidney disease that you inherit from your parents. Limitation: This is important because kidney stones increase your risk for developing chronic kidney disease. Next step: With this information, your provider will be able to recommend steps and/or medicines to help prevent more stones from forming.
- Struvite stone: Struvite is the most uncommon type of stone. It usually forms after a urinary tract infection (UTI). Limitation: This is important because kidney stones increase your risk for developing chronic kidney disease. Next step: Your treatment plan will depend on the size, type, and location of the stone.
- The test identifies the chemical composition of the stone but does not diagnose all underlying causes; follow-up with your provider is needed to determine why the stone formed and how to prevent future stones.
- Passing a kidney stone may cause pain, a urinary tract infection, or a blocked urinary tract if the stone gets stuck.
- The test itself has no known risk, but the process of collecting the stone involves passing the stone, which can be uncomfortable.
What to do next
Your treatment plan will depend on the size, type, and location of the stone. Most plans include drinking plenty of water and changing some of the foods you eat. If you have questions about your results, talk with your provider.
- What is the chemical composition of my kidney stone?
- What type of stone do I have?
- What lifestyle or dietary changes can help prevent future stones?
- Do I need any additional testing to understand why the stone formed?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.