More people are getting kidney stones, and a new study suggests that rising temperatures may have something to do with it. More than half a million people visit U.S. emergency rooms each year due to kidney stones, and a growing number of them are children.
Using the medical records of 60,000 patients in Atlanta, Chicago, Dallas, Los Angeles, and Philadelphia between 2005 and 2011, the research team found a link between hot days and kidney stones.
“We found that as daily temperatures rise, there is a rapid increase in the probability of patients presenting over the next 20 days with kidney stones,” study leader Gregory E. Tasian, M.D., M.Sc., M.S.C.E. said in a press release. The pediatric urologist and epidemiologist at The Children’s Hospital of Philadelphia is on staff at the Hospital’s Kidney Stone Center and the Hospital’s Center for Pediatric Clinical Effectiveness. The study was published in Environmental Health Perspectives.
As mean daily temps went above 50° F (10° C), risk of kidney stone presentation rose in all the cities except Los Angeles. The period between the high daily temperatures and kidney stone presentation peaked within three days of exposure to hot days.
The researchers say that the number of hot days in a given year may be a better indicator of kidney stone risk than the mean annual temperature. Atlanta and Los Angeles share the same annual temperature (63° F or 17° C), but Atlanta has far more hot days than Los Angeles, along with almost double the prevalence of kidney stones.
Interestingly, researchers also discovered that very low outdoor temperatures increased the risk of kidney stones in Atlanta, Chicago, and Philadelphia. The authors suggest that as frigid weather keeps people indoors more, higher indoor temperatures, dietary changes, and less physical activity may raise their risk of forming kidney stones.
Of note from the press release:
The study’s broader context is in patterns of global warming. The authors note that other scientists have reported that overall global temperatures between 2000 and 2009 were higher than 82 percent of temperatures over the past 11,300 years. Furthermore, increases in greenhouse gas emissions are projected to raise earth’s average temperatures by 2° to 8° F (1° to 4.5° C) by 2100.
“Kidney stone prevalence has already been on the rise over the last 30 years, and we can expect this trend to continue, both in greater numbers and over a broader geographic area, as daily temperatures increase,” concluded Tasian. “With some experts predicting that extreme temperatures will become the norm in 30 years, children will bear the brunt of climate change.”
What is a kidney stone?
A kidney stone is a solid mass formed from substances found in urine. A stone can stay in your kidney or be released into your urinary tract. You might pass a small stone without ever knowing it, but larger stones generally cause pain. If a stone gets stuck in your urinary tract, it can cause bleeding and severe pain. The hotter it is, the more likely you are to become dehydrated, which can cause kidney stones to form. According to the National Kidney and Urologic Diseases Information Clearinghouse (NKUDIC), other factors that increase your risk of forming kidney stones include:
- medications or conditions that affect the levels of certain substances in your urine
- family history of kidney stones
- recurrent urinary tract infections (UTI)
- digestive problems
Symptoms of Kidney Stones
- pain in your side or back (below the ribs)
- pain that spreads to your lower abdomen or groin
- fluctuation in pain (as the stone moves through your urinary tract)
- pain when you urinate
- constant urge to urinate or urinating more than usual
- urine that looks pink, red, brown or cloudy
- foul-smelling urine
- nausea, vomiting
- fever and chills may indicate infection
When to Call the Doctor
You should contact your doctor if you have abdominal pain. According to the Mayo Clinic, you should seek immediate medical care if you have:
- severe pain
- pain with nausea and vomiting
- pain with fever and chills
- blood in your urine
- difficulty passing urine
If you can’t pass a stone on your own, surgery may be needed.