context: Kidney stones are hard deposits made from minerals such as calcium or waste products such as uric acid. They start small, but they can grow bigger as more minerals stick to them. Some kidney stones often pass on their own without treatment. Other stones that are painful or that get stuck in your urinary tract sometimes need to be removed with surgery. You might have a procedure or surgery to take out kidney stones if: The stone is very large and can't pass on its own. You're in a lot of pain. The stone is blocking the flow of urine out of your kidney. You have had many urinary tract infections because of the stone. These four treatments can be used on your kidney stones: Shock wave lithotripsy Ureteroscopy Percutaneous nephrolithotomy or percutaneous nephrolithotripsy Open surgery Here's more about each of these: SWL is the most common kidney stone treatment. It works best for small or medium stones. It's noninvasive, which means no cuts are made in your skin. During this procedure, you lie on a table. You'll get medicine beforehand to limit any pain or discomfort. The doctor uses an X-ray or ultrasound to find the stone (or stones) in your kidney. Then, she aims high-energy shock waves at your kidney from the outside. These waves go through your skin and break up the stone into small pieces. The doctor might put a tube called a stent into your ureter (urine flows through this from your kidneys to your bladder). This stent helps the pieces of stone pass. SWL takes about an hour. You'll usually go home on the same day. Afterward, you'll drink lots of water to flush the stone pieces out in your urine. You might have to pee through a strainer to catch pieces of the stone so she can test them. SWL removes kidney stones in about half of people who have it. If it doesn't work, you might need to have the procedure repeated. The procedure can cause side effects such as cramps or blood in your urine. More serious problems are less likely, but can include: Bleeding around the kidney Infection Damage to the kidney Stone that blocks the flow of urine This procedure treats stones in the kidneys and ureters. Your doctor uses a thin, flexible scope to find and remove stones. No cuts are made in your skin. You'll sleep through this procedure. Your doctor will pass the scope through your bladder and ureter into your kidney. She uses a small basket to remove small stones. If the stones are larger, the doctor will pass a laser through the scope to break them up. You usually are able to go home on the same day. The doctor might place a stent in your ureter to help urine drain from your kidney into your bladder. You'll go back to the doctor after 4 to 10 days to have the stent taken out. Some stents have a string on the end so you can pull it out yourself. Be sure to carefully follow your doctor's instructions about taking out a stent yourself. Possible problems after a ureteroscopy include: Infection Narrowing of the ureter Bleeding If your stone is large or lithotripsy doesn't break it up enough, this surgery is an option. PCNL uses a small tube to reach the stone and break it up with high-frequency sound waves. You will be given something so that you won't be awake during this surgery. Your surgeon will make a small cut in your back or side and place a thin scope into the hole. The surgery can be done in one of two ways: Nephrolithotomy: Your surgeon removes the stone through a tube Nephrolithotripsy: Your surgeon uses sound waves or a laser to break up the stone and then vacuums up the pieces with a suction machine. The surgery takes 20 to 45 minutes. You'll typically have to stay in the hospital for a day or two afterward. Usually, a stent will have to stay in your kidney for a few days to help urine drain. Your doctor might do an X-ray or ultrasound a few weeks later to see whether any parts of the stone are left. She might also send the stone fragments to a lab to find out what they're made of. Risks from this surgery include: Infection Bleeding Damage to the bladder, bowel, ureter, kidney, or liver Open surgery is rarely done for kidney stones anymore. But if your stone is very large or it can't be removed or crushed with other treatments, surgery might be an option. Surgery may also help if: One of the stones is stuck in your ureter. You're in a lot of pain. The stone is blocking your urine flow. You're bleeding or you have an infection. You will be given something to make you unconscious during the procedure. The surgeon will make a cut in your side and into your kidney. She will remove the stone through the opening. A stent is placed in the ureter to help urine drain. You may need to stay in the hospital for a few days. It can take 4 to 6 weeks to fully heal after open surgery. Make sure you understand the risks and benefits of each of your treatment options. Ask your doctor these questions: What side effects can this surgery cause? What are the odds that it will treat my kidney stone? How long will I need to stay in the hospital afterward? What will you give me to control pain after surgery? Is there a chance I'll have to repeat the surgery?