However, when stones or loose stone fragments are small enough to leave the kidneys and enter the ureters, they can cause intense pain as they traverse, and obstruct, the urinary tract. Often stones become lodged within the urinary tract, usually within one of five particularly narrow regions. These potentially dangerous struvite stones can grow to large sizes within the kidneys. Consequently, crystals precipitate from the urine solution. The pain is typically sudden, severe, and localized to the flank of the affected side, with radiation to the groin area.
Patients commonly experience nausea and vomiting.
Generally, the urine contains either gross or microscopic blood. As an offending kidney stone passes through the ureter and approaches the bladder, burning with urination and increased urinary frequency develop. The pain disappears when the stone passes into the bladder, or moves within the ureter in such a way as to decompress the urinary system. There is a wide range of potential causes for kidney stones. Calcium stone formers often excrete abnormally large quantities of calcium in their urine.