Kidney stones are the most common disorders of the urinary tract. Kidney stones form inside a kidney when the normal substances in the urine become concentrated. Under such conditions, solid materials may stay inside your kidney, or pass down your urinary tract, and may eventually be passed out of your body. Kidney stones often don't show symptoms, especially during the early stages. They may be passed down through the urine on their own, when they are small. However, bigger sized stones may blo...