What the study found
A large, long-term study published in Mayo Clinic Proceedings reports that people who work night shifts have a 15% higher risk of developing kidney stones compared with daytime workers. The elevated risk is not limited to older adults; younger workers and those in sedentary jobs were particularly affected. The research tracked over 220,000 participants for nearly 14 years, examining shift patterns, duration, and frequency, then comparing these data with kidney stone events.
The findings suggest that shift work disrupts the body’s natural rhythms in a way that promotes stone formation. While kidney stones affect people across ages, the study highlights a sharper vulnerability among younger night shift employees, possibly because they are more likely to engage in behaviors that raise stone risk, such as inadequate hydration and irregular meals.
Why night shifts affect kidney health
The circadian clock and kidney function
Central to the issue is the body’s circadian rhythm, our 24-hour internal clock that coordinates sleep, metabolism, and organ function. Working overnight and trying to rest during the day disrupts this clock, creating metabolic and hormonal imbalances that ripple through kidney function. Lead investigator Yin Yang of Sun Yat-sen University notes that circadian disruption can alter how the body processes fluids and minerals, increasing the odds of stone formation.
Lifestyle factors tied to shift work
Beyond clock disruption, shift work can foster a constellation of stone-promoting habits: dehydration due to irregular hydration opportunities, poor sleep quality, higher BMI, smoking, and less physical activity. When these factors combine with circadian misalignment, the risk of kidney stone development rises, particularly for those in less active, desk-based roles.
Understanding kidney stones
A kidney stone is a hard deposit built from minerals and salts that can form in the kidneys and travel through the urinary tract. Stones range from tiny grains to larger blocks that cause severe pain, blood in the urine, and urinary difficulties. They’re relatively common—rates vary by region—but they are preventable with lifestyle adjustments. Recurrent stones raise concerns about future kidney health and potential complications.
Practical steps to reduce risk
Hydration basics
Hydration is one of the simplest ways to prevent stones. For most adults, aiming for 2–3 liters of water daily can help dilute urine and flush out stone-forming minerals. Individual needs vary, so consult a clinician if you have a medical condition that changes fluid requirements.
Diet and weight
Limit high-salt and processed foods, and monitor intake of animal protein, which can elevate stone risk when consumed in excess. A balanced diet rich in fruits, vegetables, and whole grains supports overall kidney health and helps maintain a healthy BMI.
Activity and sleep environment
Even if your job is sedentary, carve out time for physical activity before or after shifts. Regular movement aids metabolism and weight management, both linked to lower stone risk. Improve daytime sleep by creating a dark, quiet environment, and keep caffeine and alcohol in moderation to support more consistent rest.
When to seek medical advice
If you’ve had stones before, have a family history of kidney stones, or notice symptoms such as intense back or side pain, painful urination, blood in urine, or nausea, consult a healthcare provider promptly. A clinician can assess risk factors, check urine and blood markers, and discuss preventive strategies tailored to your work schedule and health status.
Takeaway
Night shift work is essential in many sectors, yet it can impose hidden health costs. The 15% higher risk of kidney stones identified in the study underscores the need for proactive kidney care—prioritizing hydration, smart nutrition, regular physical activity, and quality sleep. For younger night workers, awareness is particularly crucial: small daily choices can significantly influence kidney health today and in the years ahead.
Follow-up research will help refine prevention strategies, but the current evidence already offers a clear call to action: protect your circadian health, and your kidneys may thank you in return.
