Kidney stones are made of salts and minerals in the urine that stick together. 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 and includes 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).
When a stone travels through a ureter, it may cause no pain at all, or it may cause great pain and other symptoms.
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.
Call a doctor right away if you think you have kidney stones. Watch for severe pain in your side, belly, or groin or for urine that looks pink or red. You may also feel sick to your stomach (nausea) and may vomit.