Kidney stones form from crystals in the
urine. Small stones will often pass in the
urine without symptoms. Stones can
become large and block the flow of urine or
Why Do Kidney Stones Form?
Stones form for many reasons. It is common
for them to occur when the compounds that
make up stones are present at high levels in
the urine. Risk factors for kidney stones are:
ξ not drinking enough liquids
ξ abnormal urine system
ξ metabolic problems
ξ family history of kidney stones
ξ high or low intake of certain foods
Types of Stones
There are more than 50 types of kidney
stones. These are the most common.
ξ Calcium Oxalate is the most
common type of stone. It is found in
about 70% of all cases. These stones
vary in shape and size. They may be
as small as a grain of sand or as large
as a golf ball. These stones can have
a smooth or a jagged edge.
ξ Uric Acid is found in about 10% of
all cases. A high amount of uric acid
in the urine can lead to this type of
stones. People with gout are at
greater risk for this type of stone.
These stones are hard to see with
ξ Calcium Phosphate makes up about
9% of all stones. High levels of
calcium or phosphate in the urine
cause these stones to form.
ξ Struvite is found in about 9% of all
stones. They are made of
magnesium and ammonium
phosphate. An infection in the upper
urinary system can cause this type of
stone to form.
ξ Cystine makes up about 2% of all
stones. Cystine is a by-product of
the amino acid, cysteine. People
who form these stones have a genetic
trait that causes a high cystine level
in the urine. These stones look like
How Do I Know If I Have a Stone?
You may have one or more of these
ξ sharp pain in the back that comes and
ξ back pain that moves to the groin
ξ blood in the urine
ξ trouble passing urine
ξ urge to pass urine often
ξ nausea and vomiting
The only way to see and find a stone is to x-
Treatments for Kidney Stones
Many stones pass in the urine without
treatment. If a stone continues to cause pain
or a blockage, you may need further
treatment. Most stones can be treated
ξ Drink 2-3 quarts of water and other
fluids a day. This can help move the
stone along in the urinary tract.
ξ Drugs can change compounds in the
urine. By dissolving the stone or
stopping its growth, the stone can
then be passed in the urine. The type
of medicine you need depends upon
the type of stone.
If the stone does not pass and causes
constant pain, blocked urine flow, infection,
or damage to the kidney, you may need
ξ Extracorporeal Shockwave
Lithotripsy (ESWL) uses an x-ray
machine to locate the stone. Sound
waves break the stone into pieces
small enough to pass in the urine.
This works in about 85% of the cases
that need treatment. This treatment
works best for small stones in the
upper urinary tract. The sound
waves pass through your skin, there
is no incision.
ξ Ureteroscopy with laser lithotripsy.
Ureteroscopy is the examination of
the ureter and kidney. A thin, lighted
tube (called a ureteroscope) is passed
through the urethra into the bladder,
ureter, and kidney. To treat stones,
laser energy is passed through the
ureteroscope to break the stones into
tiny and/or powder like pieces that
can be passed in the urine. Most
patients go home the same day.
ξ Percutaneous Nephrolithotomy
(PCNL) treats very large or complex
stones. A small incision is made in
the back to reach the kidney. A thin
wire placed into the kidney removes
the stone. This requires a hospital
Once the stones are gone, medicine, a
change in your diet and drinking more fluids
can help to prevent stones from forming
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is not medical advice. This is not to be used for diagnosis or treatment of any medical condition. Because each
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this information. If you have an emergency, please call 911. Copyright © 10/2016 University of Wisconsin Hospitals
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