November 24, 2025

Exposure to Bright Light at Night Increases Heart Disease Risk

8 minutes

Exposure to artificial light at night disrupts your body's natural sleep-wake rhythm, raising your risk of heart disease, heart attack, stroke, and heart failure
A large-scale study found that adults living in the brightest nighttime environments had up to a 56% higher risk of heart failure and a 47% higher risk of heart attack compared to those in the darkest settings
When combined with air pollution, bright night environments amplify cardiovascular risk even more — nighttime light accounted for up to 39% of the extra heart failure risk linked to polluted air
Nighttime light not only harms your heart but also increases the risk of mental health disorders, including depression, anxiety, PTSD, and bipolar disorder, while reducing exposure to bright daylight worsens these effects
Restoring a natural light-dark cycle — bright days and truly dark nights — helps regulate your hormones, protect your heart, improve mood, and reduce your risk of chronic disease

...more

By Dr. Mercola

4.6

14871,487 ratings

November 24, 2025

8 minutes

Exposure to artificial light at night disrupts your body's natural sleep-wake rhythm, raising your risk of heart disease, heart attack, stroke, and heart failure
A large-scale study found that adults living in the brightest nighttime environments had up to a 56% higher risk of heart failure and a 47% higher risk of heart attack compared to those in the darkest settings
When combined with air pollution, bright night environments amplify cardiovascular risk even more — nighttime light accounted for up to 39% of the extra heart failure risk linked to polluted air
Nighttime light not only harms your heart but also increases the risk of mental health disorders, including depression, anxiety, PTSD, and bipolar disorder, while reducing exposure to bright daylight worsens these effects
Restoring a natural light-dark cycle — bright days and truly dark nights — helps regulate your hormones, protect your heart, improve mood, and reduce your risk of chronic disease

...more