Healthy kidneys remove waste products from your blood. These waste products leave your body in the urine your kidneys make. Your kidneys are located near the middle of your back, below your ribcage.
A kidney stone is a hard, solid lump that forms in your kidney. The lump can be as small as a tiny pebble or it can be much bigger. It is made out of the waste products in your urine. A kidney stone may stay in your kidney, or it may travel down the urinary tract (the urinary tract includes the ureters, bladder and the urethra). If the stone is big enough, it can get stuck in your kidney or urinary tract (see drawing). This can be very painful.
Kidney stones can cause a severe cramping pain in your lower back or side. The pain usually moves down toward your abdomen, groin or genitals as the stone moves down the urinary tract. Other symptoms may include:
There are four types of kidney stones:
If the stone is small enough, you might be able to pass it in your urine. Your doctor can give you medication to help with the pain.
If the stone is too big or is causing an infection, your doctor may use a special machine that uses shock waves to break up the stone into smaller pieces. This is called extracorporeal shock wave lithotripsy, or SSWL.
A urologist (urinary tract surgical specialist) can put a very thin instrument through your urethra (say: yoo-reeth-ra) and into your bladder and ureters to find the stone. He or she can then pull it out or break it into smaller pieces. If a doctor does this, you will be given medicine to numb the area first.
Surgery is also an option and is sometimes the only way to get rid of a kidney stone.
Most people who have kidney stones have a 50% chance of developing another kidney stone within 10 years. But there are things you can do to lower your risk:
If you have had more than one kidney stone, your doctor might send you to a specialist to find the exact cause of your stones. Some people need medicine to keep from getting another kidney stone
Written by familydoctor.org editorial staff