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
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
When a stone travels through a ureter, it may cause no pain. Or it may cause great pain and other
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, enough so that your urine is light yellow or clear like water (about 8 to 10
glasses a day). Some people are more likely to get kidney stones
because of a medical condition, such as gout.
may also be an inherited disease. If other people in your family have had
kidney stones, you may have them too.
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.
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
a CT scan or an ultrasound 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
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
For most stones, your doctor
will suggest that you take care of yourself at home. You may need to take pain
medicine. You'll need to drink enough water and other fluids so you don't get
dehydrated. 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 need more than home treatment.1
The most common treatment is
extracorporeal shock wave lithotripsy (ESWL). ESWL 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
After you have
had kidney stones, you are more likely to have them again. You can help prevent
them by drinking plenty of water, enough so that your urine is light yellow or clear like water, 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.
Learning about kidney stones:
Living with kidney stones:
Health Tools help you make wise health decisions or take action to improve your health.
may form when the normal balance of water, salts, minerals, and other
substances found in urine changes. How this balance changes determines the type
of kidney stone you have. Most kidney stones are
calcium-type—they form when the
calcium levels in your urine change.
Factors that change your urine balance include:
More commonly, kidney stones can run in families, as stones
often occur in family members over several generations.
cases, a person forms kidney stones because the
parathyroid glands produce too much of a hormone,
which leads to higher calcium levels and possibly calcium kidney stones.
form in the kidney. If they stay in the kidney, they typically do not cause
pain. When they travel out of the body through the tubes of the
urinary tract (including the
ureters, which connect the kidney to the bladder, or
urethra, which leads outside the body), their movement
Conditions with similar symptoms
ectopic pregnancy, and
kidney stone begins as a tiny piece of crystal in the
kidney. When the urine leaves the kidney, it may carry the crystal out, or the
crystal may stay in the kidney. If the crystal stays in the kidney, over time
more small crystals join it and form a larger kidney stone.
stones leave the kidney and travel through the
urinary tract when they are still small enough to pass easily out of the body.
No treatment is needed for these stones.
Larger stones may become stuck
in the tubes that carry urine from the kidney to the bladder (ureters). This can cause pain and possibly block the
urine from flowing to the bladder and out of the body. The pain often becomes
worse over 15 to 60 minutes until it is severe. The pain may ease when the
stone no longer blocks the flow of urine, and it often goes away when the stone
passes into the bladder. Medical treatment is often needed for larger
Problems that may occur with kidney stones include:
Kidney stones are more serious for people who have a single
kidney or an
impaired immune system or have had a kidney
When stones occur during
urologist should determine whether you need treatment.
Treatment will depend on your trimester of pregnancy.
Several risk factors (things that put you at risk) for kidney stones make it more
likely that you will get
them. Some of these things you can control, and
others you cannot.
Risk factors you can control include:
Risk factors you can't control include:
Call a doctor immediately if you have symptoms that suggest you have a
kidney stone, such as:
Call your doctor if you have been diagnosed with a kidney
stone and have another problem, such as:
Call your doctor to find out if you need an exam when
Watchful waiting is a wait-and-see approach. If
you get better on your own, you won't need medical treatment. If you get worse,
you and your doctor will decide what to do next.
If you are
passing a kidney stone under your doctor's advice, you may be able to pass the
stone without medical treatment if you:
If you need immediate help because of pain from kidney
stones, you may see an
emergency medicine specialist.
Health professionals who can diagnose and treat
kidney stones include:
To prepare for your appointment, see the topic Making the Most of Your Appointment.
Your first diagnosis of
kidney stones often occurs when you see your doctor or
go to an emergency room because you are in great pain. Your doctor or an
emergency medicine specialist will ask you questions and
examine you. After you pass a
stone, your doctor may give you another exam to find out whether you are likely
to get kidney stones again.
Your doctor may do
one or more of the following tests to help diagnose kidney stones, see where they are
located, and find out if they are causing or may cause damage to the
type of your kidney stone will help with treatment
decisions and measures to prevent stones from forming again. Tests you may have include:
For small stones, most people don't need any treatment other than taking pain medicine
and drinking enough fluids.
If your doctor
thinks the stone can pass on its own, and if you feel you can deal with the pain,
he or she may suggest home treatment, including:
Your doctor may prescribe medicine to help your body pass
To learn more, see Medications.
If your pain is too
severe, if the stones are blocking the
urinary tract, or if you also have an infection, your doctor will probably
suggest a medical procedure, such as lithotripsy, or surgery to deal with the stone. For more information, see Other Treatment and Surgery.
After you have had a
kidney stone, you are more likely to have one again. Almost half of all people
who have a stone will have more stones within 7 years unless they take
You may be able to prevent
getting more kidney stones by drinking more fluids and making changes in your
diet. Talk with your doctor or a dietitian if you need help with your diet. If you have risk factors (things that put you at risk) for having more stones, such as a family history
of stones, your doctor may suggest medicines that help prevent stones from
may need more treatment for your kidney stones if you have continuing
After you have had a kidney stone, you are more likely to have stones again. But you can take
steps to help prevent them:
If you get more kidney stones despite
drinking more fluids and making changes to your diet, your doctor may give you
medicine to help dissolve your stones or to prevent new ones from forming. For more
information, see Medications.
Home treatment—drinking more fluids and taking pain medicine—is often the only thing
you need to do when passing a
When you are
passing a kidney stone, you need to drink enough water to
keep your urine light yellow or clear like water, about 8 to 10 glasses of water a day. If you have kidney, heart, or liver disease and are on
fluid restrictions, talk with your doctor before drinking more fluids.
Medicine you can buy without a
prescription, such as
nonsteroidal anti-inflammatory drugs (NSAIDs), may relieve
your pain. NSAIDs include aspirin and ibuprofen (such as Motrin and Advil).
Your doctor can prescribe stronger pain medicine if needed.
Medicine you can buy without a
prescription, such as
nonsteroidal anti-inflammatory drugs (NSAIDs), may relieve
your pain while you pass a stone.
doctor may also prescribe medicine to help your body pass the stone.
Alpha-blockers have been shown to help kidney stones
pass more quickly with very few side effects.3 Ask
your doctor if these medicines can help you.
Which medicine you take depends on the
type of stones you have.
Calcium stones are the most common kind of kidney stone.1 To prevent them, you may take:
About 5 to 10 out of 100 kidney stones are made of uric acid, a waste product that normally exits
the body in the urine.1 To prevent these types of stones, you may take:
A very small number of stones are made of a chemical called cystine.1 Medicines to prevent them include:
Some struvite stones (staghorn calculi) form because of
kidney infections. If you have a struvite stone, you
will most likely need antibiotics to cure the infection and help prevent new
stones from forming. You may need surgery to remove the
stone. Urease inhibitors may be used to prevent struvite stones.
Surgery is rarely needed to treat kidney stones. Surgery is only needed when the kidney stone is very large, caused by an infection (staghorn calculi), blocking the flow of urine out of the kidney, or causing other problems like severe bleeding.
If your kidney stones were caused by a problem with your parathyroid gland, your doctor may suggest surgery to
remove a parathyroid gland or glands (parathyroidectomy). This can help prevent future kidney stones.
Other treatments for kidney stones are much more common than surgery. You may need one of these treatments if your pain is very bad, your stone is blocking the urinary tract, or you have an infection. Your options include:
Whether these treatments will work for you will depend on the size of the stone, its location in the urinary tract,
and your overall health.
UrologyHealth.org is a website written by urologists
for patients. Visitors can find specific topics by using the "search"
The website provides information about adult and
pediatric urologic topics, including kidney, bladder, and prostate conditions.
You can find a urologist, sign up for a free quarterly newsletter, or click on
the Urology A–Z page to find materials about urologic problems.
The National Kidney and Urologic Diseases Information
Clearinghouse (NKUDIC) provides information about diseases of the
kidneys and urologic system to people with these problems and to
their families, to health professionals, and to the public. NKUDIC answers
inquiries; develops, reviews, and distributes publications; and works closely
with professional and patient groups and government agencies to
coordinate resources about kidney and urologic diseases.
NKUDIC, a federal agency, is a service of the National
Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). NIDDK is part
of the National Institutes of Health under the U.S. Department of Health and
The National Kidney Foundation works to prevent kidney
and urinary tract diseases and help people affected by these conditions. Its
website has a lot of information about adult and child conditions. The site
has interactive tools, donor information, recipes for kidney disease patients,
and message boards for many kidney topics. Free materials, such as brochures
and newsletters, are available.
CitationsParmar MS (2004). Kidney stones. BMJ, 328(7453): 1420–1424.Teichman JMH (2004). Acute renal colic from ureteral calculus. New England Journal of Medicine, 350(7): 684–693.American Urological Association and European Association of Urology (2007, reaffirmed 2010). Ureteral Calculi: 2007 Guideline for the Management of Ureteral Calculi. Available online: http://www.auanet.org/content/guidelines-and-quality-care/clinical-guidelines.cfm?sub=uc.Other Works ConsultedMoe Ow, et al. (2010). Nephrolithiasis. In EG Nabel ed., ACP Medicine, section 10, chap. 12. Hamilton, ON: BC Decker.Stoller ML (2008). Urinary stone disease. In EA Tanagho, JW McAninch, eds., Smith's General Urology, 17th ed., pp. 246–277. New York: McGraw-Hill.Taylor EN, et al. (2005). Obesity, weight gain, and risk of kidney stones. JAMA, 293(4): 455–462.
April 28, 2011
Anne C. Poinier, MD - Internal Medicine & Tushar J. Vachharajani, MD, FASN, FACP - Nephrology
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