Midwest Stone Institute
What is a Kidney Stone
Stones that form in the kidneys and urinary tract are one of the most painful disorders to afflict human beings.
More than a million Americans are hospitalized each year for the treatment of kidney and urinary tract stones. Today surgery is rarely necessary, as recent medical advances have improved understanding and increased the possibility that many cases of stone disease can be cured or controlled with noninvasive or endoscopic therapies.
A kidney stone is usually a hard mass that builds up gradually when various salt or mineral crystals deposit on the inner surfaces of the kidney. As stones irritate the lining of the kidney, bleeding may occur in the urine.
This bleeding often leads the individual to visit a physician, who may detect the stone if it is opaque on X-ray examination.
Sometimes a stone will break off from its location in the kidney pelvis, resulting in severe pain as it moves down the urinary tract.
What Are "Urinary" And "Bladder" Stones?
The urinary system consists of two kidneys, located below the ribs toward the middle of the back; two drainage tubes called ureters, connect the kidneys to the bladder in the lower abdomen; and the urethra, the tube through which urine flows from the bladder to outside of the body.
Kidney stones that remain in the kidney or that break loose from the lining of the kidney and move to other parts of the kidney or ureter are sometimes referred to as "upper tract stones." Sometimes smaller stones pass through the ureters and lodge in the bladder where they enlarge, or stones may originate in the bladder. In either case, these are referred to as "lower tract" stones.
When stones grow so large that they cannot be passed out of the body easily, they obstruct the normal flow of urine, causing pain and possibly infection or kidney damage. Many stones are too large to pass out of the kidney. Other stones may leave the kidney only to become lodged in the ureter , or rarely at the outlet of the bladder.
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