Where are
bladder stones produced?
It is not unusual for tiny crystals
to form in the urine of healthy people, as many of
the substances eliminated by the kidneys are only
just soluble in water. A change in the acidity of
urine, for example, can change the chemical
environment of the urine enough to cause crystals
to form. Provided these crystals remain small
enough, they are flushed out without causing any
symptoms or trouble. Some people do however have
an increased tendency to form urine stones, either
starting within the kidney and ending up in the
bladder, or forming within the bladder itself. A
structural abnormality of the bladder such as
blind pouch might encourage this by producing a
'stagnant' area that does not drain properly when
passing urine. Another complicating factor is
infection of the urine, which can be due to and
encourage the further growth of bladder stones. In
older men an enlarged prostate can encourage the
growth of a bladder stone by restricting the
proper and full drainage of the bladder.
Whereas a stone of only a few millimetres in size
can easily cause great pain if it gets held up
during its travel through the narrow ureter - the
tube linking the kidney and bladder (renal colic),
a bladder stone can be several centimetres in size
and not necessarily give symptoms, providing it
doesn't block the emptying of the bladder itself,
which is of course much more roomy.
What are
the symptoms of a bladder stone?
Many people walk around with a
bladder stone for years without noticing. But if
the bladder stone irritates the mucosa (soft
lining) of the bladder, blood may appear in the
urine. Typically the blood will appear towards the
end of urination.
A bladder stone may also cause pain when
urinating. If the stone gets stuck at the entrance
to the urethra, the jet of urine will suddenly
stop in the middle of urinating.
How is a bladder
stone detected?
A bladder stone can be detected
through an X-ray with or without a dye test or
ultrasound equipment. It can also be found by
cystoscopy - where a tube-shaped instrument is
inserted into the bladder through the urethra.
Smaller bladder stones can be removed during this
examination. When they are bigger, it may be
necessary to operate.
An alternative treatment available in some centres
is lithotripsy, in which the stone is reduced to
smaller fragments by sound energy. This technique
can also be used to shatter stones within the
kidneys - often these are too large and complex in
shape to be removed in any other way. |
