The incidence of painful kidney stones is on the rise in the U.S. According to the National Kidney Foundation, about 1 in 10 people will experience a kidney stone at least once during their lifetime. A new study found that at least part of the increase is due to the use of CT scans that find stones that would have gone undiagnosed in the past.
Kidney stones have increased from 3.8 percent in the late 1970s to 8.8 percent thirty years later, increasing the lifetime risk to about 19 percent in men and 9 percent in women. The risk increased twofold in men and fourfold among women.
Symptoms of kidney stones, which are compounds that crystallize into stones in the kidneys, include severe pain on either side of the lower back, blood in the urine, nausea or vomiting, and fever and chills. Kidney stones can range in size from as small as a grain of sand to as large as a golf ball. They cause pain when a stone causes irritation or blockage.
The new study focused on gender, age and stone formation, and included people diagnosed with kidney stones for the first time between 1984 and 2012.
Researchers found that people with kidney stones who experienced symptoms tended to be female, and the highest increase was noted in women ages 18 to 39. Bladder stones were less frequent and tended to be more noticeable in men due to prostatic obstructions. Women had a higher frequency of stones causing infection as a result of recurrent urinary tract infections.
"Symptomatic kidney stones are becoming more common in both men and women," said lead researcher Dr. Andrew Rule. "This is due in part to the increased use of CT scans to diagnose kidney stones."
"We are now diagnosing symptomatic kidney stones that previously would have gone undiagnosed because they would not have been detected."
The study appears in Mayo Clinic Proceedings.
Doctors try to get kidney stones to pass without surgery by asking the patient to drink a lot of water. But if it's too large, is blocking urine, or causing an infection, surgery is recommended. Techniques include lithotripsy, which uses sound waves to break the stone into fragments that can be passed in urine, or ureteroscopy, using an endoscope to retrieve or eliminate the stone. More invasive surgery is necessary if the stone is too large or can't be broken up by lithotripsy.
There could be a new way to cure kidney stones — doctors may soon prescribe a ride on a roller coaster, according to a study published in The Journal of the American Osteopathic Association.
The study, conducted at Michigan State University, was prompted by patients who reported passing kidney stones after riding Disney World's Big Thunder Mountain Railroad. One patient passed a stone following each of three consecutive rides.
A device mimicking a kidney filled with urine along with three kidney stones no larger than 4 millimeters in size was placed aboard the ride. Results showed that riding on the back seat showed a stone passage rate of 63 percent. An expanded study showed a success rate of almost 70 percent, and a 100 percent passage rate if the stones were located in the upper chamber of the kidney.
But choose your ride carefully: "The ideal coaster is rough and quick with some twists and turns, but no upside down or inverted movements," said researcher David Wartlinger. While Big Thunder Mountain Railroad was a thundering success, Space Mountain and Aerosmith's Rock 'n' Roll Coaster failed.