Kidney stone of 13 mm can be considered for extracorporeal lithotripsy if the conditions are met such as the stone is in the renal pelvis or in the upper or middle calyces of the kidney, and the CT value of HU is less than 1,000 as well as the distance of the stone from the skin on the surface of the body is less than 10 centimeters. The indications for extracorporeal lithotripsy for kidney stones are as follows: 1. renal pelvis stones or upper and middle calyceal stones with a diameter of less than 1 cm. 2. Intrapelvic or suprarenal or middle calyceal stones with a diameter of 1 to 2 centimeters and a CT value of HU (a unit of measurement for determining the density of local tissues or organs) of less than 1,000, with the vertical distance from the skin to the stone on the surface of the body being less than 10 centimeters. 3. Lower calyceal stones with a diameter of less than 1 centimeter. 4. Partial staghorn-shaped stones with a diameter of 2 to 3 centimeters or a surface area of less than 5 square centimeters. It can be seen that kidney stones 13 mm can be considered for extracorporeal lithotripsy if the second point above is satisfied. Contraindications for extracorporeal lithotripsy for kidney stones include bleeding disorders, luminal obstruction at the distal end of the stone, severe diabetes mellitus, episodes of urinary tract infection, and pregnancy in women. Therefore, whether it is suitable for extracorporeal lithotripsy needs to be judged by the doctor according to the patient’s individual situation.