Sometimes the stones stay in the kidneys when they are asymptomatic, but they can also travel through the urinary system. Pain from kidney stones typically occurs when they move through the urinary system. A small stone may pass so easily you may not even notice it. But larger stones can get stuck and cause blockages. When a kidney stone causes a blockage, urine backs up into the organs of the urinary tract. This backup of urine and the irritation of the stone itself can both cause excruciating pain.