kidney stone disease

Kidney stone disease or urinary stone disease is a crystallopathy that occurs when there is an excess of minerals in the urine and not enough liquid or hydration. This imbalance causes tiny crystals to aggregate and form hard masses, or calculi (stones), in the upper urinary tract. Because renal calculi typically form in the kidney, if small enough they may pass out of the urinary tract through the urine stream. A small calculus may pass without causing any symptoms. However, if a stone grows to more than 5 millimeters (0.2 inches), it can cause blockage of the ureter, resulting in extremely sharp and severe pain (renal colic) in the lower back that often radiates to the groin. A calculus may also result in blood in the urine, vomiting (owing to severe pain), swelling of the kidney, or painful urination. About half of all people who have had a kidney stone are likely to develop another within ten years.

Renal is Latin for "kidney", while nephro is the Greek equivalent. Lithiasis (Greek) and calculus (Latin; plural calculi) both mean stone.