What is a kidney stone?
kidney stone is a hard, pebble-like deposit that forms in the kidney. -Most are as small
as a grain of sand or as large as a pearl. Rarely, they can be as big as golf balls. A
stone may be smooth, irregular in shape, or jagged. Most are yellow or brown in color.
There are different types of kidney stones:
stones. Calcium stones are the most common type of stones. Calcium is a
normal part of a healthy diet and is used by bones and muscles. Calcium not used by
the body goes to the kidneys where it is normally flushed out with the urine. In some
people, the calcium that stays behind bonds with other waste products to form a
stones. Struvite stones contain the mineral magnesium and the waste product
ammonia. It may form after an infection in the urinary tract.
- Uric acid
stones. Uric acid stones may form when there is too much acid in the urine.
This can be seen in people who have gout.
stones. Ceystine is one of the building blocks that make up muscles, nerves,
and other parts of the body. It can build up in the urine and form a stone. Cysteine
stones are rare. This form of the disease runs in families.
Kidney stones are one of the most painful disorders. They are also one of the most
common problems of the urinary tract.
What causes a kidney stone?
A kidney stone develops from crystals
that build up in the kidney. Urine normally contains chemicals that prevent or slow the
crystals from forming. But stones still form in some people. Small crystals can travel
through the urinary tract and pass out of the body in the urine without even being
noticed. A larger stone can get stuck in a ureter. The ureter is the small tube between
the kidney and the bladder. A large stone can also get stuck in the bladder or the
urethra. The urethra is the tube from the bladder that takes urine out of the body. A
large stone may block the flow of urine and cause great pain.
Who is at risk for kidney stones?
You are more likely to get a kidney stone if you:
- Are white. Whites are at higher risk than African Americans
- Are male. Kidney stones happen more often in men, but the number of women who get
kidney stones has been growing.
- Are age 20 to 40.
- Have had a stone in the past. Once you’ve had one stone, you are more likely to
These are factors you can control:
much fluid you drink. If you don’t drink enough fluids and tend to be dehydrated, you
are at a higher risk for kidney stones.
diet. Eating a diet that is high in protein, sodium, and dark green vegetables
(oxalate-rich types of foods), can increase your risk for kidney stones.
weight. Being overweight increases insulin resistance in your body. Insulin
resistance increases the amount of calcium filtered into the urine. In turn, this
increases the risk of developing a kidney stone.
- Medicines. Some medicines can increase your risk for kidney stones. Common medicines
include water pills (diuretics) and antiviral medicines.
These things you can't control:
diseases. Diseases that cause ongoing higher levels of calcium in the blood. More
calcium can cause dehydration because you make more urine. The extra calcium in the
kidney solidifies into a stone.
- Surgery. Surgeries on the digestive tract including the intestines and gastric
bypass can make you more likely to have long-term (chronic) dehydration. Or you may
develop diseases that cause chronic diarrhea and dehydration. These increase the risk
for kidney stones.
history. Inherited factors or a family history of kidney stones can raise your
urinary tract infections that kept returning
estrogen. Women with low estrogen levels after menopause or after removal of the
ovaries are at greater risk for kidney stones.
Men between the ages of 30 and 50 are the most likely to get kidney stones.
uric acid level. Diseases that raise uric acid levels (gout) raise your risk for
- Diabetes. Insulin resistance from diabetes can cause an increase the amount of
calcium filtered into the urine. This raises the risk for a kidney stone.
What are the symptoms of kidney stones?
These are the most common symptoms of kidney stones:
- Extreme, sharp pain in the back or side that will not go away. Changing positions
doesn't help. Pain can come and go.
- Blood in
or odorous urine
- Frequent urination
burning feeling when you urinate
symptoms of kidney stones may look like other health problems. Always talk with
your healthcare provider for a diagnosis.
How are kidney stones diagnosed?
healthcare provider will ask about your health history and do a physical exam. You may
have other tests. These include:
pyelogram (IVP). This is a series of X-rays of the kidney, ureters, and
bladder with the injection of a contrast dye into the vein. It helps find tumors,
kidney stones, or blockages. It can also check blood flow to the kidney.
scan. This is an imaging test that uses X-rays and a computer to make
detailed images of the body. A CT scan shows details of the bones, muscles, fat, and
- Urinalysis. This is a lab exam of urine for various cells and chemicals,
such as red blood cells, white blood cells, infection, or extra protein.
tests. These are lab exams of the blood to look for substances that might
cause stone to form. These tests can also assess how well your kidneys are
ultrasound. A noninvasive test in which sound waves are bounced off the
kidney. The test sends a picture of the kidney to a video screen. The test is used to
find the size and shape of the kidney. It can also see a mass, kidney stone, cyst, or
other blockage in the kidney.
How are kidney stones
Treatment will depend on your symptoms, age, and general health. It
will also depend on how severe the condition is.
your healthcare provider right away if you think you have a kidney stone. Some kidney
stones pass out of the body on their own without treatment. In cases that cause lasting
symptoms or other complications, kidney stones may be treated with one of the
- Shock waves
or extracorporeal shock wave lithotripsy (ESWL). This treatment uses a
machine to send shock waves directly to the kidney stone. This breaks a large stone
into smaller stones that will pass through the urinary tract. There are 2 types of
shock wave machines. In one, you sit in a tub of water. In the other, you lie on a
- Ureteroscope. A long wire with a camera attached to it is inserted into the
urethra. The wire is passed up through the bladder to the ureter where the stone is
located. A tiny cage is used to grab the stone and remove it.
surgery (percutaneous nephrolithotomy). A small cut is made in your back and
a narrow tunnel is made through the skin to the stone inside the kidney. The surgeon
can remove the stone through this tunnel.
Potassium citrate. Your healthcare provider may prescribe potassium citrate
tablets to treat stones made of calcium and urate. You take the tablets with plenty
of fluids. The citrate may help dissolve and drain the stone with the additional
Can kidney stones be
The best ways to prevent kidney stones are:
- Drink more water. Up to 12 glasses of water a day can help to flush away the substances that form stones in the kidneys. Ginger ale, lemon-lime sodas, and fruit juices are also OK.
- Limit coffee, tea, and cola to 1 or 2 cups a day. The caffeine may cause a rapid loss of fluid.
- Talk with your healthcare provider or a dietitian about any diet changes.
medicines prescribed to prevent calcium and uric acid stones from forming.
When should I call my healthcare provider?
Let your healthcare provider know if
your symptoms get worse or you have new symptoms.
Key points about kidney stones
- A kidney
stone is a piece of hard sediment that forms in the kidney. It develops when certain
substances that are filtered in the urine crystallize and stick together in the
kidney creating a stone.
stones are made of calcium, although stones can be formed from other substances.
- Dehydration and certain medicines also increase the risk for kidney stones.
stones cause pain with urination as the stone passes through the urinary tract.
kidney stones can't be passed out of your body because they are too large and become
stuck in the urinary tract. This causes great pain.
- You may
be able to prevent kidney stones by staying away from certain foods and drinking
plenty of water.
- Once you
have had a kidney stone, you are more likely to have another stone.
Tips to help you get the most from a visit to your healthcare provider:
- Know the reason for your visit and what you want to happen.
- Before your visit, write down questions you want answered.
- Bring someone with you to help you ask questions and remember what your provider tells you.
- At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.
- Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.
- Ask if your condition can be treated in other ways.
- Know why a test or procedure is recommended and what the results could mean.
- Know what to expect if you do not take the medicine or have the test or procedure.
- If you have a follow-up appointment, write down the date, time, and purpose for that visit.
- Know how you can contact your provider if you have questions.
Online Medical Reviewer:
Ronald Karlin MD
Online Medical Reviewer:
Walead Latif MD
Date Last Reviewed:
© 2000-2018 The StayWell Company, LLC. 800 Township Line Road, Yardley, PA 19067. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.