What do my kidneys do?
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.
What is a kidney stone?
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.
Written by familydoctor.org editorial staff