WEATHER UPDATE: All Providence hospitals in Oregon are open. Clinics in the Portland area may delay opening or close early due to weather conditions. Please call in advance. View clinic schedule updates ›
A kidney stone is a hard, pebble-like deposit that forms in the kidney. It may be as small as a grain of sand or as large as a pearl - some are as big as golf balls; a stone may be smooth, irregular in shape, or jagged.