A kidney stone is a solid mass made up of tiny crystals. One or more stones can be in the kidney or ureter at the same time.
Renal calculi; Nephrolithiasis; Stones - kidney; Calcium oxalate - stones; Cystine - stones; Struvite - stones; Uric acid - stones; Urinary lithiasis
Kidney stones are common. Some types run in families. They often occur in premature infants.
There are different types of kidney stones. The cause of the problem depends on the type of stone.
Stones can form when urine contains too much of certain substances that form crystals. These crystals can develop into stones over weeks or months.
Calcium stones can also form from combining with phosphate or carbonate.
Other types of stones include:
The biggest risk factor for kidney stones is not drinking enough fluids. Kidney stones are more likely to occur if you make less than 1 liter (32 ounces) of urine a day.
You may not have symptoms until the stones move down the tubes (ureters) through which urine empties into your bladder. When this happens, the stones can block the flow of urine out of the kidneys.
The main symptom is severe pain that starts and stops suddenly:
Other symptoms can include:
The health care provider will perform a physical exam. The belly area (abdomen) or back might feel sore.
Tests that may be done include:
Stones or a blockage can be seen on:
Treatment depends on the type of stone and the severity of your symptoms.
Kidney stones that are small most often pass through your system on their own.
Some people with severe pain from kidney stones need to stay in the hospital. You may need to get fluids through an IV into your vein.
For some types of stones, your provider may prescribe medicine to prevent stones from forming or help break down and remove the material that is causing the stone. These medicines can include:
Surgery is often needed if:
Today, most treatments are much less invasive than in the past.
Talk to your provider about what treatment options may work for you.
You will need to take self-care steps. Which steps you take depend on the type of stone you have, but they may include:
Kidney stones are painful, but most of the time can be removed from the body without causing lasting damage.
Kidney stones often come back. This occurs more often if the cause is not found and treated.
You are at risk for:
Complication of kidney stones may include the obstruction of the ureter (acute unilateral obstructive uropathy).
Contact your provider if you have symptoms of a kidney stone:
If you have been diagnosed with blockage from a stone, passage must be confirmed either by capture in a strainer during urination or by follow-up x-ray. Being pain free does not confirm that the stone has passed.
If you have a history of stones:
American Urological Association website. Medical management of kidney stones (2019). www.auanet.org/guidelines-and-quality/guidelines/kidney-stones-medical-mangement-guideline. Updated 2019. Accessed May 25, 2022.
American Urological Association website. Surgical management of stones: AUA/Endourology Society guideline (2016). www.auanet.org/guidelines-and-quality/guidelines/kidney-stones-surgical-management-guideline. Updated 2016. Accessed May 25, 2022.
Bushinsky DA. Nephrolithiasis. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 117.
Fink HA, Wilt TJ, Eidman KE, et al. Recurrent nephrolithiasis in adults: comparative effectiveness of preventive medical strategies. Rockville, MD. Agency for Healthcare Research and Quality (US) 2012;Report No.:12-EHC049-EF. PMID: 22896859 pubmed.ncbi.nlm.nih.gov/22896859/.
Miller NL, Borofsky MS. Evaluation and medical management of urinary lithiasis. In: Partin AW, Dmochowski RR, Kavoussi LR, Peters CA, eds. Campbell-Walsh-Wein Urology. 12th ed. Philadelphia, PA: Elsevier; 2021:chap 92.
Reviewed By: Kelly L. Stratton, MD, FACS, Associate Professor, Department of Urology, University of Oklahoma Health Sciences Center, Oklahoma City, OK. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.