Extracorporeal shock wave lithotripsy is most suitable for stones of about 1.0 cm. For extracorporeal shock wave lithotripsy, the main purpose is to locate the stone by X-ray or ultrasound, and then use high-energy shock wave to focus on the stone, causing it to crack until it is powdered or finely sanded and excreted through urine. According to the indications of urological guidelines, stones smaller than 2 cm can be treated by extracorporeal shock wave lithotripsy, but clinically the best results are achieved for stones of about 1 cm. Generally 1 extracorporeal shock wave lithotripsy can effectively break up stones. Stones larger than 1 cm but smaller than 2 cm may require 2-3 sessions to break up the stones.