Kidney stones, renal calculi and urinary stones are different names for crystalline structures which form in the urinary tract from the excretion of excess minerals in the body. 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. 
                  The average kidney stone forms in about 90 days. As blood flows through the kidneys, impurities are filtered along with excess minerals produced by cells within the body. The collected impurities remain and eventually mix with water then leave the body as urine. Occasionally the trapped minerals build up in the kidney. A kidney stone is usually a hard mass formed by the trapped crystallized minerals that deposit on the inner 
                    surfaces of the kidney. As stones irritate the lining of the 
                    kidney, bleeding may occur in the urine. 
                  This bleeding warrants medical attention and evaluation. A  stone may be detected if visible on plain X-ray or a CT Scan may be needed. 
                    Sometimes a stone will break off from its location in the 
                    kidney and may result in severe pain as it travels down the urinary tract toward your bladder. 
                  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.  |