Every year, an estimated 177,496 people over the age of 20 were diagnosed with kidney stones. But why do people get kidney stones, anyway?

There are many reasons why people get kidney stones. Photo: Shutterstock

Over the course of just one year, an estimated 177,496 people over the age of 20 were admitted to the hospital and diagnosed with kidney stones. Statistics also show that approximately 2 million adults were diagnosed with kidney stones during visits with primary care doctors or specialists. In that same year, about 2.7 million adults with “urolithiasis” (formation of stones in the kidneys, ureters, or bladder) as their diagnosis.

That’s not the only bad news, though: it is estimated that one in 10 Americans (about 30 million people) will experience a kidney stone at some point in their lives. And if you happen to be a white man, your risk is substantially higher than other populations. The annual incidence of kidney stones increased 16 percent between 1997 and 2012.

This begs the question—why do people get kidney stones, anyway? There are a few key risk factors.


The reason kidney stones develop in the first place is a disturbance in the delicate balance of water, minerals, salts, and other substances in the body. This is most commonly caused by dehydration. If you’re not drinking enough water, levels of these substances can rise and kidney stones could be the result.


Unfortunately, if someone in your family has suffered from kidney stones, you are more at risk to develop them as well. For example, one gene defect can cause hypercalciuria (too much calcium in the urine), which makes it more likely that the individual will develop a calcium stone. I’ve also mentioned a few more hereditary conditions below in the “Diseases and Medical Conditions” section.


Taking certain medications can also impact your chances of becoming a kidney stoner. The medications that can increase the risk of kidney stones generally fall into these categories: decongestants, anticonvulsants, steroids, and chemotherapy drugs.

Diseases and Medical Conditions

Some diseases and medical conditions can increase your risk of developing kidney stones, too.

  • Primary hyperparathyroidism causes the body to produce abnormally high levels of the hormones produced by the parathyroid glands. This leads to bone weakness due to loss of calcium and can also lead to kidney stones.
  • Renal tubular acidosis is a condition in which acid builds up in the body because the kidneys cannot acidify the urine.
  • Hyperoxlauria (say that three times fast!) occurs when the kidneys have to eliminate high levels of oxalate in the urine, either because you eat or produce too much of it.
  • Cystinuria is a rare condition where kidney stones are made from an amino acid called cystine. This amino acid leads to the formation of stones in the kidney, ureter, and bladder.
  • Urinary tract infections can introduce bacteria into the kidneys, ureters, bladder, or urethra. These bacteria can lead to the formation of bladder and/or kidney stones.
  • Gout, a form of arthritis in which uric acid builds up in the joints, can also lead to an increased risk of uric acid stones.

Metabolic Syndrome

In 2014, research from the National Kidney Foundation showed that the terrible pain of kidney stone disease may be more common in people who have a condition called metabolic syndrome. This condition is a cluster of five traits that also sets the stage for heart disease and stroke. A report in the American Journal of Kidney Diseases showed that people with metabolic syndrome are three times more likely to get kidney stones than those who don’t.

The study shows that being overweight was a central factor in this syndrome, so maintaining a healthy weight was important to reducing the risk of kidney stones. Other components of metabolic syndrome include diabetes; high levels of triglycerides; low HDL cholesterol, also known as “good” cholesterol; and high blood pressure.

If you don’t want to be one of the “lucky winners” of the kidney stone lottery, make sure you drink enough water, keep to a healthy weight, and, of course, read my book, Even Urologists Get Kidney Stones, for more information on treating and preventing kidney stones.