How big kidney stones get depends on the type of stone. For example, a staghorn stone can grow so large as to fill the entire kidney.
Kidney stones are solid masses most commonly made of calcium but also sometimes caused by too much uric acid, magnesium, or cystine. The larger they get, the more pain they cause, especially when your body tries to pass them in your urine. They can become stuck in your urethra, bladder or urethra.
Variety of Sizes
The smallest kidney stones are so tiny you might not even realize you have them. They can be as small as a grain of sand. However, they can become much bigger. Some are the size of pearls or golf balls. The largest, called staghorn stones, can get so big they fill the entire kidney. Staghorn stones are different from most kidney stones because they are caused by infections.
Not all kidney stones look alike. Some are smooth; others are bumpy or jagged. Most are yellow or brown.
How They Are Formed
Kidney stones are created by your kidneys, the organs in the middle of your back. Your kidneys sift waste and extra water from your blood, combining them to form urine that passes from your body. Sometimes waste material builds up and creates a stone.
What to Do
If you think you have a kidney stone, call your doctor. Symptoms can include chronic pain in your back or side, discomfort during urination and blood in the urine. Most kidney stones pass through the body without a doctor's help, but some require medical intervention. Stones that are bigger than about ½ inch usually won't pass without complications. Your doctor can also advise you on how to prevent future stones.