Page 2 - Kidney Stones

Kidney stones
number of stones formed in the past, and the person’s
age at the time of the first stone formation.
Treatment of kidney stones
Treatment of kidney stones is sometimes required
for the relief of pain or obstruction. Many stones
will pass in the urine without specific treatment.
Occasionally, shock waves are used to fragment a
large stone into smaller particles that will pass more
easily. A stone trapped in a ureter can often be
removed with instruments introduced through the
urethra (bladder outlet). More difficult stones may
require surgical removal through a small incision. All
of these treatments may not be available at your
local hospital. The treatment recommended by your
urologist will depend on the specific circumstances
of your stone problem.
Prevention of kidney stones
The mainstay of kidney stone prevention is a high
fluid intake to maintain dilute urine. Although it is
recommended that all stone formers should try
to produce between two and three litres of urine
per day, any increase in fluid intake is beneficial.
Additional fluid should be consumed when fluid losses
increase with heavy perspiration or diarrhea.
Ideally, about half of your daily fluid intake should be
water. There is no clear evidence that hard water is
worse than soft water in preventing kidney stones.
Almost all fluids will be helpful in reducing the risk of
stone formation. Some fluids, such as iced tea, cocoa
and cranberry juice, may contain substances that
are found in many kidney stones. These fluids are less
helpful in stone prevention.
Severe restriction of dietary calcium is not
recommended for the prevention of kidney stones,
and indeed, in some persons, it may even aggravate
stone formation. Calcium restriction may also increase
the risk of developing bone problems in older people.
You should not reduce your dietary calcium without
consulting your doctor.
This publication is produced by
The information in the publication is not intended to convey medical advice or to substitute for direct consultation with a qualified medical
practitioner. The Canadian Urological Association disclaims all liability and legal responsibility howsoever caused, including negligence, for the
information contained in or referenced by this brochure.
© 2014. Canadian Urological Association. All rights reserved.
An important constituent of many stones is oxalate.
The body produces most of the oxalate in the urine
as a by-product, while a portion is derived from
one’s diet. Oxalate is found in high levels in spinach,
rhubarb, cranberries, strawberries, blackberries,
chocolate, nuts, beet greens, squash, cola, cocoa
and tea. Calcium oxalate stone formers should avoid
consuming excessive amounts of these foods.
A high intake of meat, fish and poultry increases the
risk of stone formation. This applies particularly to
uric acid stone formation, but also to calcium stone
formers. Your animal protein consumption should be
limited to 250 grams (eight ounces) daily.
A high salt intake is associated with increased
excretion of calcium in the urine, even though
salt does not contain calcium. Salt restriction is
recommended for stone formers. A high fibre diet
may provide additional benefit.
It is important that these dietary alterations become
permanent lifestyle changes. These changes should
be adopted gradually, starting with an increase in
fluid intake and a reduction in dietary salt. Once this
becomes a habit, additional dietary modifications
can be introduced if stone formation continues to be
a problem. Your physician can help you determine
which dietary modifications would be beneficial to
you.
Follow-up
Some kidney stone formers should be monitored
regularly. In these cases, an annual simple x-ray
(without injection of “dye”) or ultrasound examination
of the kidneys is sufficient. Any dietary, medication
and health changes can be reviewed at that time.
More frequent follow-up may be required in recurrent
stone formers, children and those with kidney
problems.
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