Heat And Dehydration Can Increase The Risk Of Painful Kidney Stones, Ascension Saint Thomas Physician Warns

August is historically one of the hottest months in Middle Tennessee, and this year's forecast calls for more days of intense heat and humidity. Ascension Saint Thomas clinicians say staying hydrated is one of the best ways to protect against heat-related illness and reduce the risk of developing painful kidney stones.

"The kidneys act as the body's natural filtration system, removing waste and excess minerals through urine," said Dr. Brian Wilcox, Chief Clinical Officer for Ascension Saint Thomas. "When you're well hydrated, urine stays diluted, making it easier for those minerals to pass through the body. But when you're dehydrated, urine becomes more concentrated, allowing minerals like calcium, oxalate, and uric acid to stick together and form crystals that can eventually become kidney stones."

The risk increases during periods of extreme heat when the body loses significant amounts of fluid through sweating. Without replacing those fluids, urine output decreases and creates an environment where kidney stones are more likely to form.

"Many people don't realize how quickly dehydration can occur during the summer, especially if they're working outdoors, exercising, or spending long periods in the heat," Wilcox said. "For someone who is already prone to kidney stones, even a few days of inadequate hydration can trigger symptoms."

Kidney stones may not cause symptoms until they begin moving through the urinary tract. Common warning signs include:

• Severe pain in the lower back, side, or abdomen
• Pain or burning during urination
• Cloudy or foul-smelling urine
• Frequent or urgent need to urinate
• Nausea or vomiting

While anyone can develop kidney stones, the risk is higher for people who:

• Have a history of kidney stones
• Do not drink enough water throughout the day
• Eat diets high in sodium or animal protein
• Have obesity or certain metabolic conditions
• Spend extended periods outdoors in hot weather

The best defense against kidney stones is staying well hydrated. Ascension Saint Thomas clinicians recommend:

• Drinking enough water to keep urine light yellow or nearly clear
• Replacing fluids lost through heavy sweating, including beverages with electrolytes when appropriate
• Limiting sugary drinks and excessive sodium, which can increase the risk of stone formation
• Wearing lightweight clothing and taking breaks in the shade when working or exercising outdoors
• Avoiding prolonged outdoor activity during the hottest part of the day whenever possible

"Hydration is one of the simplest and most effective ways to protect your kidneys," Wilcox said. "If you experience severe side or back pain, pain with urination, or notice blood in your urine, don't ignore those symptoms. Seeking care early can prevent complications and connect you to the treatment you need."