KIDNEY STONES

Kidney stones, also known as Renal Calculi, are one of the most

common disorders of the urinary tract. In the U.S. alone, over one million people suffer from kidney stones each year. A kidney stone is ¡§a solid lump (from as small as a grain of sand to as large as the size of a golf ball) made up of crystals that separate from urine and build up on the inner surfaces of the kidney.Between 70% and 90% of crystals remain tiny enough so that they can travel through the urinary tract and pass out of the body without being noticed. When they cause symptoms, however, kidney stones have been described as one of the most painful disorders to afflict human beings. A kidney stone normally begins as a tiny speck of solid material deposited in the middle of the kidney, where urine collects before flowing into the ureter. As more material clings to the first speck, it gradually builds into a solid object. This process can occur in one or both kidneys. Kidney stones can be composed of a variety of substances. The most common types of kidney stones include calcium stones, uric acid stones and struvite stones. About 70% to 80% of all kidney stones are comprised of calcium and phosphate, or calcium and oxalate. About 7% of stones are made up of uric acid. Uric acid is a crystal that is the end product of purine metabolism. Another 5% of stones are made of magnesium ammonium phosphate and are referred to as struvite stones. There are many potential causes of kidney stone formation. In general they are all a result of a super concentration of chemicals in the urine that results in crystals being formed.