Kidney stones are made of salts and minerals in the urine that stick together to form small "pebbles." They can be as small as grains of sand or as large as golf balls. They may stay in your kidneys or travel out of your body through the urinary tract.
The urinary tract is the system that makes urine and carries it out of your body. It is made up of the kidneys, the tubes that connect the kidneys to the bladder (the ureters), the bladder, and the tube that leads from the bladder out of the body (the urethra).
Kidney stones form when a change occurs in the normal balance of water, salts, minerals, and other things found in urine. The most common cause of kidney stones is not drinking enough water. Some people are more likely to get kidney stones because of a medical condition or family history.
Kidney stones may also be an inherited disease. If other people in your family have had kidney stones, you may have them too.
Kidney stones often cause no pain while they are in the kidneys. However, when a stone travels through a ureter it may cause sudden, severe pain and other symptoms. Watch for:
For most stones, your doctor will say you can stay at home until they pass. You may need to take pain medicine and/or other medication to help the stone pass.
If a stone is too large to pass on its own, or if it gets stuck in the urinary tract, you may need more treatment. About 1 or 2 out of every 10 kidney stones need medical attention.
The most common medical treatment is extracorporeal shock wave lithotripsy (ESWL). ESWL uses shock waves to break a kidney stone into small pieces. The bits can pass out of your body in your urine. Other times, a doctor will need to remove the stone or place a small flexible plastic tube (called a stent) in the ureter to keep it open while stones pass.
After you have had kidney stones, you are more likely to have them again. You can help prevent them by drinking enough water to keep your urine clear, about 8 to 10 glasses of water a day. You may have to eat less of certain foods. Your doctor may also give you medicine that helps prevent stones from forming.