Kidney stone HP:0000787 Nephrolithiasis Kidney stones Kidney stones (calculi) are mineral concretions in the renal calyces and pelvis that are found free or attached to the renal papillae. UMLS:C0392525 Renal calculi Renal stones HP:0000102 Nephrolithiasis is derived from the Greek words nephros (kidney) and lithos (stone) and the suffix iasis (process) and refers to the condition of having one or more kidney stones. In practice, nephrolithiasis is used interchangably. In contrast to nephrolithiasis, diffuse renal parenchymal calcification is called nephrocalcinosis. Stones that develop in the urinary tract (known as nephrolithiasis or urolithiasis) form when the urine becomes excessively supersaturated with respect to a mineral, leading to crystal formation, growth, aggregation and retention within the kidneys. Crystals or foreign bodies can act as a nidus for further stone formation. The resulting kidney stones (calculi) lead to symptoms if they become impacted in the ureter. Abnormal renal morphology