Kidney stones are hard collections of salt and minerals that form in your kidneys and can travel to other parts of your urinary system. Stones cause symptoms like pain, trouble urinating, cloudy or smelly urine, nausea and vomiting. Some stones will pass on their own.

This is the most common treatment in the U.S. It works best for small or medium stones. Your doctor aims high-energy sound waves to break up the kidney stone into little pieces. The shock waves come from outside the body, which is why the procedure sometimes is called extracorporeal SWL.