Kidney stones Patient information from the BMJ Group

Patient information from the BMJ Group
Kidney stones
Having a kidney stone can be painful and distressing. Most stones pass out of the
body without any treatment. But for those that don't, there are good treatments
What are kidney stones?
Kidney stones are solid, stone-like lumps that can form in your kidneys. They are made
from waste chemicals in your urine. Stones can also form in your bladder and the tubes
that carry urine from your kidneys to your bladder (these are called ureters).
Stones can stay in your kidneys without causing problems. But some might travel out of
your body in the flow of urine. If they are very small, they can pass out of your body
without you noticing. But larger ones can rub against the tubes or even get stuck. This
can be extremely painful.
There are four types of kidney stones.
The most common type contains calcium. These stones are called calcium oxalate
Uric acid stones form if there is too much uric acid in your urine. Uric acid is a waste
product made when food is digested.
Struvite stones develop after a urinary infection, such as cystitis.
Cystine stones are caused by a rare inherited condition called cystinuria.
It is important to know what kind of stone you have, as this will affect your treatment to
prevent future stones.
What are the symptoms?
The main symptom is pain. This can be a dull ache in your back or side, or an extremely
sharp, cramping pain. The pain usually comes on suddenly. It might spread down to your
tummy or groin. You might also:
Feel sweaty or sick
Be sick
Find blood in your urine. This is caused by the stone rubbing against the walls of
the ureter
Need to urinate more often or feel a burning sensation when you urinate.
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Kidney stones
Your doctor is likely to suspect you have a kidney stone if you have sudden, severe pain
in your side and blood in your urine. You'll probably be sent to hospital for an x-ray. If
you have a kidney stone, these tests may show how big the stone is and where it is stuck.
If the x-ray does not show a kidney stone, you will probably have more tests to find out
what's causing the pain.
You may not get any symptoms with a kidney stone. You might find out you have one
when you have an x-ray for another reason.
What treatments work?
Stones that are less than 1 centimetre across often pass out of the body without any
treatment. It can take two days to four weeks for this to happen.
You can help the process along by drinking plenty of water to increase the flow of urine.
You'll also need to take strong painkillers for the pain.
If you have a stone stuck in a tube (ureter), your doctor might recommend taking a
medicine called an alpha-blocker. This type of drug is often used to treat high blood
pressure or symptoms of an enlarged prostate, but studies show it can also help stones
to pass through the ureters faster.
You'll probably be able to stay at home during this time, although you may need x-rays
to check on the progress of the stone.
Your doctor may ask you to catch the stone with a tea strainer or something similar as
it comes out. This is so your doctor can see what type of stone you have. Knowing the
type of stone will help them work out what you can do to prevent more stones.
Surgical treatments
Larger stones and those that don't pass out of the body need treatment. All the following
treatments work well.
Shock wave therapy uses shock waves to break up stones into small pieces that
can pass out of the body. Many stones are dealt with this way and it avoids any
operation. You might sit in a tub of water or lie on a table to have this treatment.
You'll have a local anaesthetic in the area that's being treated.You may need several
treatments to break up hard or large stones. The risk of side effects after this
treatment is small. But you could get an infection in your kidney or a stone stuck in
your ureter afterwards.
You may need a minor operation if a stone in your kidney is large or in an awkward
place. It's called a percutaneous nephrolithotomy (PCNL).You need a general
anaesthetic for this, and you will probably have to stay in hospital. The doctor makes
a small cut in your back and passes a needle and a very thin tube into your kidney
to remove the stone. Like all operations, there can be problems (complications). The
main ones are constipation and infections.
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Kidney stones
If the stone is stuck in a tube (ureter), you may have a ureteroscopy. You don't
need any cuts made in your body for this, and you can probably go home the same
day. You can have a local or general anaesthetic. The doctor feeds a long, thin wire
up through your bladder and into the ureter to reach the stone.The doctor then either
removes the stone or breaks it up with shock waves. This procedure works well, but
it does have risks. In one study, about 1 out of 10 people who had this treatment
had a damaged or torn ureter afterwards.
What will happen to me?
If you've had a kidney stone you have about a 1 in 2 chance of getting another one within
five years to seven years.
Your doctor can prescribe medicines to help stop you getting some types of stones. The
type of medicine you get depends on the type of stone you've had. For example, you
may need to take diuretics (water pills) to reduce calcium in your urine if your stone
contained calcium. Or if you have too much uric acid in your urine you might be given a
drug called allopurinol (the brand names are Caplenal, Cosuric, and Zyloric).
Your risk of getting more stones may also be affected by what you eat and drink. To
reduce your risk, you can:
Drink more than two litres of water a day
Eat a healthy diet, including calcium but not calcium supplements. Foods rich in
calcium include milk and other dairy products, peas and beans, leafy green
vegetables, nuts, and bony fish like sardines and salmon
Avoid using lots of salt
Eat more vegetables. Vegetables make the urine less acidic.
If you've had a calcium oxalate stone, you may need to reduce the amount of oxalate in
your diet. This means cutting down on chocolate, nuts, rhubarb, strawberries, spinach,
coffee, and tea.
But changes in diet don't work for everyone, and there is not a lot of evidence to show
how well they work. So it's important to talk to your doctor before making big changes
to what you eat.
This information is aimed at a UK patient audience. This information however does not replace medical advice.
If you have a medical problem please see your doctor. Please see our full Conditions of Use for this content.
For more information about this condition and sources of the information contained in this leaflet please visit the Best
Health website, . These leaflets are reviewed annually.
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Kidney stones
© BMJ Publishing Group Limited 2014. All rights reserved.
Last published: Sep 05, 2014
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