following are the frequently asked questions answered by
Dr. C. Chinnaswami, M.S., M.Ch, F.R.C.S., Chairman,
TNURC, Kidney Stone Clinic, Chennai.
Has the incidence of urinary stones increased ?
true, incidence of stones in the kidney and ureter has increased
in recent times, whereas the bladder stones that were common
in children are not to be seen now a day.
Possible causes for the increase could be due to changes
in life style, contributed by
· Increase in salt intake
· Increased intake of animal proteins.
· Low intake of fibers and alkalis
· Inadequate water intake.
· Use of food preservatives.
What chemical abnormalities are known to cause kidney stones?
chemical abnormalities relate to the type of stones that
form in the kidneys. These four types of stones and the
chemical abnormalities that cause them are:
Stones: people who form this type of stone either have too
much of one type of three chemicals in their urine, or not
enough of another. In particular, they have either too much
calcium, oxalate, or urate in their urine, or too little
citrate. Eating too much salt may cause too much calcium
to stay in the urine A few patients will have kidney stones
from overproduction of the calcium controlling hormone,
parathormone. Drinking milk does not cause kidney stones.
Stones: Chronic infection of the urine generally causes
these stones. The bacteria responsible for the infection
cause a chemical alteration of urine, which leads to this
type of stone.
Stones: These stones form because of an inborn error of
metabolism of Alanine. Abnormal amount of cystine accumulates
in the body which leads to stone formation. Usually, other
family members have the same condition.
the type of kidney stone is important to prescribing treatment
to prevent further stone formation.
3. Where do urinary stones
formed and where are they found?
is commonly seen in the kidney and ureters. Bladder stones
are common in children and in elderly persons. Most of the
stones are formed in the minute tubules of the kidney and
pass down. It may stay in the kidney and grow bigger or
it may stay in the ureter. Majority of the stones can easily
slip down to the bladder and pass out in natural way. It
may get lodged at various levels and grow larger.
4. How do the stones form
in urinary tract ?
Kidney excretes out large quantity of minerals and end products
of metabolism and maintains the internal equilibrium of
the body. The minerals are in a super saturated but soluble
forms. When the balance is upset either by increase in concentration
of the salts (as seen in dehydration due to sweating or
diarrhea or poor intake of fluids) or turbulence of urinary
stream or presence of materials like bacteria, dead papillae
(tissue in kidney) tumor or foreign bodies on which the
salts gets deposited and stone starts to grow.
Urinary stone has been compared to ferroconcrete in structure.
It is not formed of pure crystals as in blue metal. There
is a scaffolding formed by colloids, dead bacteria, tumor
tissue or foreign body (like steel rods in concrete) and
salts in the urine oxalate, uric acid, triple phosphate
or cystine crystalline materials fill in the space between
crystals grow well in alkaline urine whereas some stones
grow only in acidic urine. Many stones grow rapidly in stagnant
urine, which gets collected above obstructed urinary tract.
What are the symptoms of urinary stones ?
Pain is the commonest presenting symptoms. It may be severe,
shooting from the back towards the
thigh or genitalia. This happens when the stone moves from
the kidney to the ureter. It is called
renal colic or ureteric colic.
which are inside the kidney, may not cause severe pain but
dull aching pain may be felt in
the kidney area. It is a perplexing but surprising fact
that big stones may remain and grow silently
whereas small stones can cause severe pain when they move
– passing blood in the urine is another common feature
of urinary stones. This blood in
the urine could be quite obvious to the naked eye or only
a microscope could detect it. Severity or
quantum blood is not dependent on the size of the stone.
C) Fever may be associated with pain in stone disease. It
points to the presence of infection.
– this term is used to denote presence of pain on
touching (palpating) various areas of
the abdomen. This is to be distinguished from pain
mentioned earlier. Presence of tenderness denotes
the last two symptoms fever and tenderness are noted the
stone problem should be considered
serious and treated promptly.
– it is unusual to see any significant swelling in
simple stone disease. It may be seen in stones
of long duration.
Nausea or Vomiting – may be associated with severe
pain. It may also be a sign of kidney failure associated
with some kidney stones.