Kidney stones result from the precipitation (crystallization of previously dissolved particles) of
certain substances within the urine. These stones form in the kidney and subsequently
travel through the ureter (the tube that conducts
urine from the kidney to the bladder) and are eliminated through the urine
if they are small. In some cases, the stone may not be able to travel through
the ureter, causing pain and possibly causing an obstruction, blocking the
flow of urine out of the kidney. Kidney stones can be caused by a large number
of factors, such as infection, certain diets, medications, and conditions
that result in an increased concentration of calcium or other substances,
including oxalate and uric acid, in the urine. The composition of the stone
depends on the cause, but the most common type of stone contains calcium.
The March 2, 2005, issue of JAMA includes an article
that reviews the causes and diagnosis of kidney stones and the available treatments.
The symptoms associated with kidney stones vary depending on the size
of the stone, its position within the urinary tract, and whether there is
an associated kidney infection.
In addition to a complete medical history and physical examination,
your doctor may order blood tests to assess your kidney function and the concentration
of certain electrolytes and dissolved minerals (such
as calcium) in your blood. A urinalysis (analysis
of a small sample of urine for infection and blood) and a 24-hour urine collection
(to look for substances associated with kidney stones) may also be performed.
Your doctor may order a computed tomography (CT) scan, abdominal x-ray, or
ultrasound test to locate the stone and to rule out other possible causes
of the symptoms.
Initial treatment includes pain medication and
oral or intravenous fluid to help the stone pass through the urine.
Extracorporeal shock wave lithotripsy is a procedure that uses shock waves to break up the stone without
the need for surgery.
Surgery may be necessary if the stone is very large
and if there is blockage of the affected kidney or infection.
Depending on the cause of your kidney stone, your
doctor may prescribe medication or suggest dietary changes to prevent a recurrence.
To find this and previous JAMA Patient Pages, go to the Patient Page
link on JAMA's Web site at http://www.jama.com. Many are available in English and Spanish.
Sources: National Institute of Diabetes and Digestive and Kidney Diseases;
National Kidney Foundation
The JAMA Patient Page is a public service of JAMA. The information and recommendations appearing on this page are appropriate
in most instances, but they are not a substitute for medical diagnosis. For
specific information concerning your personal medical condition, JAMA suggests that you consult your physician. This page
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TOPIC: KIDNEY DISORDERS