For Patients

What are kidney stones?

Kidney stones affect more than a million Americans each year. Twelve to 24 million Americans will develop stones in their lifetime and the incidence rate has increased dramatically over the last 20 years with approximately 350,000 new stone cases reported each year.

Kidney stones are created by a buildup of crystalline material like calcium and other salts, which collect in the kidney to form a stone. The stones can be as small as a grain of sand or as large as a golf ball. The size, shape, and location of the stone can cause many different symptons.

A person with kidney stones may experience severe pain or none at all. The amount of pain depends on how quickly the stone causes a blockage of urine flow. If a stone travels quickly from the kidney into the kidney tube (ureter), it can create an acute blockage of urine flow, causing the kidney to swell and resulting in intense pain.

Other signs of kidney stone disease include blood in the urine, recurring urine infections, severe nausea and vomiting. Most pain is located in the back, but can move toward the front of the lower abdomen or the flank. When a stone grows slowly within the kidney, little or no pain may be felt.

Kidney stone disease is two to three times higher in men than in women, and three to four times more frequent in whites than blacks, with middle-aged white men having a a 20% chance of getting kidney stones over their lifetime. The risk for women is only 5% to 10%. Once a person has a kidney stone, their chance of getting another one ranges from 65% to 90%. Interestingly, people living in the southeastern United States, also known as the stone belt, have the highest chance of getting kidney stones.