Over time, minerals (called ‘stones’) can settle in your kidneys. Extracorporeal Shock Wave Lithotripsy (ESWL) is a procedure that uses sound waves (also called shock waves) to break these stones into smaller pieces so that they can pass from your body in your urine.


ESWL is generally a safe procedure with few, if any, risks. These risks include:

Urinary tract infection.
Bleeding around the area where the stones were crushed.
Pain when the smaller fragments pass through your urinary tract.
Inability to pass urine if the stone fragments block your urinary tract.

Procedure Description

When the sound waves strike the stones, it can cause discomfort or pain. For this reason, you will be given medication prior to your ESWL. You will be given a sedative prior to the procedure and medication for discofort during the procedure.
The sound waves travel best through water. During your ESWL, you will be placed in a tub of water, or you will lie on a water-filled cushion. If your procedure is done using a tub of water, you may be placed in a harness and lowered gently into the water, or you may sit on a chair in the tub of water. Your upper body will remain out of the water.

X-ray or ultrasound (a test that uses high-frequency sound waves to produce images of the inside of your body) will be used. Your doctor can see where your stones are and aim the sound waves precisely at the stones. Your ESWL may last from thirty minutes to one hour.

After your ESWL, you will remain in the recovery area for two or three hours so that your temperature and heart rate can be monitored. In most cases, you will go home the same day.