Extracorporeal shock wave lithotripsy (ESWL) is the most common way of treating kidney stones that cannot be passed in the urine. It involves using X-rays (high-energy radiation) or ultrasound (high-frequency sound waves) to pinpoint where a kidney stone is. A machine then sends shock waves of energy to the stone to break it into smaller pieces so it can be passed in your urine.
ESWL can be an uncomfortable form of treatment, so it is usually performed after giving painkilling medication.
You may need more than one session of ESWL to treat your kidney stones successfully. ESWL is up to 99% effective for stones that areup to 20mm (0.8in) in diameter.