"Silent" kidney stones produce no pain, but
most stones cause pain so severe that it's unforgettable.
Some even say that it's even more painful than childbirth.
It may come in waves that begin in your lower back
move to your side or groin. Other symptoms of stones
are nausea, fever, bloody urine, or burning on urination.
You may also have risk factors, like a family history
of stones, that make you more likely to have stones
in the future.
What are kidney stones?
Within the kidney, miniature filters separate substances
from your blood that your body doesn't need, which
excrete in urine. But under certain conditions, chemicals
in the urine may form crystals. These crystals
up in the kidney and stick together to form a stone.
Kidney stones may block the flow of urine through
urinary tract, causing severe pain.
How Kidney Stones Form
Fluid loss (dehydration) can make your urine so concentrated
that stones form. Certain foods contain high amounts
of the chemicals that sometimes crystallize into stones.
Kidney infections foster stones by slowing urine flow
or changing the acid balance of your urine.
The location, size, and shape of your stone usually
determine your symptoms. Many stones cause sudden and
severe pain, bloody urine, or infection. Others cause
nausea or frequent, burning urination.
The size, shape and composition of your kidney stone
help determine its cause and whether your stone is
likely to pass by itself or if it will require more
|A stone may be
as small as a grain of sand or as large as a golf
ball. Many small stones pass naturally. Medium-sized
stones are often crushed with special "high-tech"
equipment. Very large stones may need to be removed
using an invasive procedure.
round stones may pass easily if they are small.
with sharp edges often lodge inside the kidney
or ureter. Staghorn stones, which can fill
entire kidney, are too large to pass naturally.
|Many stones are
made up of more than one chemical. Most stones
are made of calcium oxalate, a hard salt compound.
Very hard stones sometimes don't respond well
to Extracorporeal Shock Wave Lithotripsy (ESWL).
Cystine and uric acid stones are also dense,
sometimes can be dissolved with medication. Infection
stones are less dense.
The vast majority of kidney stones are small enough
-- about the size of a grape seed -- to pass naturally,
a "wait and see" approach. It's very likely
you'll be able to pass your stone naturally with expectant
lots of water:
helps flush out stones by increasing urine production.
Water also reduces your risk of new stones by
diluting the chemicals in your urine. Drink 12
eight-ounce glasses of water a day and avoid liquids
that dehydrate you, such as caffeine and alcohol.
your stone for analysis by your doctor, strain
all your urine. Use the strainer whenever you
urinate, for as long as your doctor suggests.
Be on the lookout for brown, gold, or black specks
or tiny pebbles. These are kidney stones.
find a stone, bring it in to your doctor for analysis.
The type of stone you have will determine the
diet and prevention program your doctor recommends.
You may need additional tests and x-rays in the
future to ensure that new stones are not forming.
stones can recur at any time, so your prevention
program lasts a lifetime. Drink lots of water,
follow your diet, take your medications, and have
Depending on what your stone is made of your doctor
may be able to prescribe medication to dissolve them.
|Medication cannot dissolve
calcium oxalate stones, but are often helpful
in preventing them.
|Uric Acid or Cystine
|If you have a uric
acid or cystine stone, your doctor may prescribe
medications to dissolve your stone. You may take
these medications for the rest of your life.
acid stones are caused by an overproduction of
uric acid, which can be worsened by a high-meat
diet. Cystine stones are uncommon and are inherited,
a result of too much cystine (an amino acid)
|If you have an infection
stone, your doctor may prescribe antibiotics.
When your infection is under control, your doctor
can remove your stone. Infections stones are caused
by kidney or bladder infections that change the
chemical balance of your urine.
Extracorporeal Shock Wave Lithotripsy (ESWL)
If your kidney stone won't pass naturally
or can't be dissolved with medications, you may be
good candidate for ESWL. This noninvasive procedure
safely and effectively "shatters" your stone
without surgery, using an energy source outside your
body. For this procedure, you lie in a comfortable
position on a water cushion and your doctor focuses
waves directly at your stone. With pinpoint accuracy
the shock waves hit your stone, making it crumble
sand-like particles, which then pass easily through
your urinary tract. It may take more than one ESWL
to ensure fragmentation; or you may need an additional
procedure, such as the insertion of a tube "stent"
in the ureter
to help passage of larger stones, before ESWL can be
|Shockwaves from an energy source travel to your
stone which begins to crack.
|The stone crumbles into fine sand after thousands
for a Lifetime
If you've felt the pain of a kidney stone, you may worry
that you'll have another. Removing or passing your stone
starts your treatment process, but it doesn't prevent
future stones. Fortunately, with your doctor's help,
you can reduce your risk of forming new stones.
- Drink lots of water. Staying
well-hydrated is the most important way to reduce
your risk of future stones. Drink 12 eight-ounce
glasses of water every day, two with every meal
and two between meals. Try keeping a pitcher of
water at your side.
- Follow your prescribed diet.
Your doctor will tell you which foods contain the
chemicals you should avoid. Your doctor may also
recommend that you consult with a dietitian, who
can help you plan enjoyable meals that won't put
you at risk for future stones.
- Take your medications.
If your doctor prescribes medications for your stone,
you may want to write your doses and medication
times on a calendar. There are several types of
medications used to prevent kidney stones.
- See your doctor regularly.
Regular visits to your doctor will help you detect
new stones early and ensure that old stones are
gone. Depending upon your type of stone, you may
follow up every three months to once a year for
Notice: Information on this web site is provided for informational
purposes only and is not a substitute for professional medical advice. You
should not use the information on this web site for diagnosing or treating
a medical or health condition. If you have or suspect you have a medical
problem, promptly contact your professional healthcare provider.