Definition for kidney stone

Kidney stones, or renal calculi, are solid concretions (crystal aggregations) of dissolved minerals in urine; calculi typically form inside the kidneys or ureters. more

Kidney stones, or renal calculi, are solid concretions (crystal aggregations) of dissolved minerals in urine; calculi typically form inside the kidneys or ureters. The terms nephrolithiasis and urolithiasis refer to the presence of calculi in the kidneys and urinary tract, respectively. Renal calculi can vary in size from as small as grains of sand to as large as grapefruit. Kidney stones typically leave the body by passage in the urine stream, and many stones are formed and passed without causing symptoms. If stones grow to sufficient size before passage--on the order of at least 2-3 millimeters--they can cause obstruction of the ureter. The resulting distention with urine can cause severe episodic pain, most commonly felt in the flank, lower abdomen and groin (a condition called renal colic). Renal colic can be associated with nausea and vomiting due to the embyrological association of the kidneys and the intestinal tract. Recurrence rates are estimated at about 10% per year. less