Page 1 - Kidney Stones
P. 1

Urological Health



                                Kidney stones








        Stones may form in the kidneys, occasionally blocking the drainage of urine and causing pain.





           he kidneys play an important role in eliminating       Low urine output may be due to inadequate fluid
        Twaste products from the body. These waste                intake or excessive fluid losses, such as with frequent
        products normally remain dissolved in the urine as it     heavy perspiration or chronic diarrhea. Alternatively,
        passes through the kidney drainage system (calyces,       the urine may be overloaded with a substance
        renal pelvis and ureter). Kidney stones are crystalline   because of excessive dietary intake, excessive
        particles that form in the urine, often producing pain    production by the body, or changes in the function of
        when they obstruct urine drainage from a kidney.          the bowels or kidneys. Kidney stones are rarely a sign
                                                                  of kidney disease and stone formation is uncommon in
                                                                  people with poorly functioning kidneys.

                                                                  Most often kidney stones take many months or
                                                                  years to grow to a size that can produce symptoms,
                                           kidneys                generally, by obstructing urine drainage from a
                                                                  kidney. Occasionally, stones may form more rapidly.
                                           stone                  Because stones usually do not cause symptoms
                                           in calyx               soon after they are formed, it is impossible to know
                                                                  how rapidly a person’s stone or stones have formed.
                                                                  Approximately 50% of stone formers will develop a
                                           stone                  second kidney stone within 10 years of their first stone,
                                           obstructing            and 75% within 20 years.
                                           ureter

                                           ureters                Stone types
                                                                  Most kidney stones contain calcium, usually calcium
                                           bladder                oxalate or calcium phosphate. About 10% of kidney
                                                                  stones are composed of uric acid, a by-product of
                                           urethra                breakdown of meat, poultry and fish products, which
                                                                  is excreted in higher concentration in people with
                                                                  gout. Struvite stones occur in association with certain
        Approximately one in ten Canadians will develop a         bacterial infections of the urine.
        kidney stone. This problem is more common in men
        than in women, and it occurs rarely in children. Kidney   Investigation of kidney stones
        stone formation in most adults is not thought to be an
        inherited condition even if several family members        Most kidney stones can be seen on a simple x-ray.
        have had stones. Children with kidney stones,             Uric acid stones, however, are not visible on simple
        however, are more likely to have an inherited risk.       x-rays and require other investigations. An ultrasound
        Some children have severe forms of stone disease that     or a CT scan is often very useful in identifying the
        require thorough investigation and frequent follow-up.    size and location of all types of kidney stones. An
                                                                  IVP (intravenous pyelogram) is occasionally ordered
        Kidney stone formation                                    and involves an intravenous injection of “dye” that is
                                                                  excreted in the urine, demonstrating the presence of
        Kidney stones form when the concentration of certain      a stone and the function of the kidneys.
        substances in the urine exceeds the amount that stays     Urine and blood tests will help in monitoring kidney
        dissolved. This can happen when the urine becomes         function and determining the cause of kidney stone
        over-concentrated due to low urine volume or
        excessive excretion of a substance.                       formation. The frequency of tests recommended
                                                                  depends on the severity of the stone disease, the

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