Why night shifts might hurt your heart
A Systematic Review of Literature on the Association Among Sleep, Cortisol Level and Cardiovascular Health Within the Healthcare Shift Worker Population
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Cortisol levels are lower in the morning and higher at night in shift workers—exactly the opposite of healthy rhythm.
Most people assume cortisol just goes up with stress, but this shows the timing matters more than the amount. Even if you’re not stressed, your body’s clock is broken.
Practical Takeaways
If you work nights and have trouble sleeping, prioritize treating your insomnia—cognitive behavioral therapy for insomnia (CBT-I) may reduce your heart disease risk.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Cortisol levels are lower in the morning and higher at night in shift workers—exactly the opposite of healthy rhythm.
Most people assume cortisol just goes up with stress, but this shows the timing matters more than the amount. Even if you’re not stressed, your body’s clock is broken.
Practical Takeaways
If you work nights and have trouble sleeping, prioritize treating your insomnia—cognitive behavioral therapy for insomnia (CBT-I) may reduce your heart disease risk.
Publication
Journal
Biomedicines
Year
2025
Authors
Aslah Nabilah Abdull Sukor, N. Juliana, Nazefah Abdul Hamid, N. Teng, Muslimah Ithnin, S. Azmani, S. Kasim
Related Content
Claims (5)
People who work nights or irregular shifts in healthcare tend to have less healthy heart rhythms, which means their hearts aren't recovering as well—and this is linked to a higher chance of heart problems, even if they're young or live a healthy lifestyle.
When your body's internal clock is out of sync—like from shift work or jet lag—it messes up your stress hormones, stops your sleep hormone from working right, and turns on inflammation in the same way that being tired or stressed for a long time does.
People who work night shifts or irregular hours tend to have weird cortisol patterns—low in the morning and high at night—which seems to make their sleep worse. This might be because their body’s internal clock is out of sync with their work schedule.
Nurses who work nights and have trouble sleeping are much more likely to develop heart problems, even when you account for their age, weight, and work hours—suggesting that just having insomnia might be a hidden danger for their hearts.
Working irregular shifts messes up your body clock, which makes it harder to sleep well. Poor sleep raises a stress hormone called cortisol, which then makes your sleep and heart function even worse over time — raising your risk of heart problems.