(renal stone) Crystals in the pelvis of the kidney.

(kidney stones) A kidney stone is a solid piece of material that forms in the kidney from substances in the urine. It may be as small as a grain of sand or as large as a pearl. Most kidney stones pass out of the body without help from a doctor. But sometimes a stone will not go away. It may get stuck in the urinary tract, block the flow of urine and cause great pain. The following may be signs of kidney stones that need a doctor's help: Extreme pain in your back or side that will not go away; Blood in your urine; Fever and chills; Vomiting; Urine that smells bad or looks cloudy; A burning feeling when you urinate. Your doctor will diagnose a kidney stone with urine, blood, and imaging tests. If you have a stone that won't pass on its own, you may need treatment. It can be done with shock waves; with a scope inserted through the tube that carries urine out of the body, called the urethra; or with surgery. NIH: National Institute of Diabetes and Digestive and Kidney Diseases

Stones in the KIDNEY, usually formed in the urine-collecting area of the kidney (KIDNEY PELVIS). Their sizes vary and most contains CALCIUM OXALATE.

(renal calculi) A disorder characterized by the formation of crystals/kidney stones in the pelvis of the kidney.

Kidney stones (also called renal calculi, nephrolithiasis or urolithiasis) are hard deposits made of minerals and salts that form inside your kidneys.

Kidney stone, concretion of minerals and organic matter that forms in the kidneys. Such stones may become so large as to impair normal renal function. Urine contains many salts in solution, and if the concentration of mineral salts becomes excessive, the excess salt precipitates as crystals that...