Kidney Stones

Topic Overview

What are kidney stones?

Kidney stones are made of salts and minerals in the urine that stick together to form small "pebbles." They can be as small as grains of sand or as large as golf balls. They may stay in your kidneys or travel out of your body through the urinary tract . The urinary tract is the system that makes urine and carries it out of your body. It is made up of the kidneys, the tubes that connect the kidneys to the bladder (the ureters), the bladder, and the tube that leads from the bladder out of the body (the urethra).

When a stone travels through a ureter, it may cause no pain. Or it may cause great pain and other symptoms.

See pictures of a kidney stone and a stone traveling through a ureter .

What causes kidney stones?

Kidney stones form when a change occurs in the normal balance of water, salts, minerals, and other things found in urine. The most common cause of kidney stones is not drinking enough water. Try to drink enough water to keep your urine clear (about 8 to 10 glasses of water a day). Some people are more likely to get kidney stones because of a medical condition or family history.

Kidney stones may also be an inherited disease. If other people in your family have had them, you may have them too.

What are the symptoms?

Kidney stones often cause no pain while they are in the kidneys, but they can cause sudden, severe pain as they travel from the kidneys to the bladder.

Call a doctor right away if you think you have kidney stones. Watch for severe pain in your side, belly, or groin or for urine that looks pink or red. You may also feel sick to your stomach (nausea) and may vomit.

How are kidney stones diagnosed?

You may first find out that you have kidney stones when you see your doctor or go to an emergency room with pain in your belly or side. Your doctor will ask you questions about your pain and lifestyle. He or she will examine you and may do imaging tests such as X-rays to look at your kidneys and urinary tract.

You may need more tests if you have more than one stone or have a family history of stones. To find out the cause of your kidney stones, your doctor may order a blood test and ask you to collect your urine for 24 hours. This can help your doctor find out if you are likely to have more stones in the future.

Kidney stones may not cause any pain. If this is the case, you may learn you have them when your doctor finds them during a test for another disease.

How are they treated?

For most stones, your doctor will suggest drinking enough water to keep your urine clear, or about 8 to 10 glasses of water a day, to help flush the stones out. You may also need to take pain medicine. You can do this at home. Your doctor may give you a medicine to help the stone pass.

If a stone is too large to pass on its own, or if it gets stuck in the urinary tract, you may need more treatment. About 1 or 2 out of every 10 kidney stones needs more than home treatment.¹

The most common medical treatment is extracorporeal shock wave lithotripsy (ESWL). This uses shock waves to break a kidney stone into small pieces. The bits can pass out of your body in your urine. Other times, a doctor will need to remove the stone or place a small flexible plastic tube (called a stent) in the ureter to keep it open while stones pass.

Will I have kidney stones again?

After you have had kidney stones, you are more likely to have them again. You can help prevent them by drinking enough water to keep your urine clear, about 8 to 10 glasses of water a day. You may have to eat less of certain foods. Your doctor may also give you medicine that helps prevent stones from forming.

Frequently Asked Questions

Learning about kidney stones:	What are kidney stones? What causes a kidney stone? Can I prevent kidney stones? What are the symptoms of kidney stones? What happens when you have kidney stones? What increases my risk for getting kidney stones? What are the types of kidney stones? Who is affected by kidney stones?
Being diagnosed:	Who can diagnose kidney stones? How are kidney stones diagnosed?
Getting treatment:	How is a kidney stone treated? What medicine will I need to take? Will I need surgery? What other treatments are available? Should I use extracorporeal shock wave lithotripsy (ESWL) for my kidney stones?
Living with kidney stones:	What can I do at home for kidney stones? What do I need to do if my kidney stones come back? How can I change my diet to prevent kidney stones?

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Author:	Monica Rhodes	Last Updated May 30, 2007
Medical Review:	Adam Husney, MD - Family Medicine Philip Belitsky, MD, FRCSC - Urology
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