Harvard study warns: Common napping habits linked to higher death risk

Napping – once celebrated as the “siesta” – has always been portrayed as a sweet afternoon indulgence – a momentary escape, a boost of productivity, or just a welcomed pause. Think of power naps as the snooze buttons that reset our mental sharpness during a demanding day.

However, all that glitters ain’t gold!

Likewise, all that looks ‘healthy’ on the surface doesn’t necessarily have only health benefits.

A new large-scale study from Harvard Medical School and Massachusetts General Hospital challenges this rosy picture, suggesting that some nap patterns might be a silent alarm bell for health trouble.


What’s happening?

A new Harvard Medical School and Massachusetts General Hospital study is sounding a grim alarm. Tracking over 86,000 adults (average age 63) with wearable devices and following them for 11 years, the researchers found that certain napping patterns – specifically, longer, irregular, or midday-heavy sleeps – were significantly associated with higher all-cause mortality, even after controlling for BMI, alcohol, smoking, and nighttime sleep.

Unlike past research based on self-reports, this study tapped objective tracking – via wearable devices worn for seven days – offering fresh insight into daylight dozing habits and long-term outcomes.



The reality of ‘nappiness’

Napping is deeply ingrained in cultures—Mediterranean siestas, polar day naps, even Silicon Valley’s nap pods. And there are contexts where naps clearly boost alertness and productivity—think pilots on long-haul flights, or caregivers catching a moment’s rest.

However, your mid-day resting habits can also predict how soon you’ll lie down to “rest your eyes” — and not get back up.

Previous research has focused on the link between nighttime sleep and mortality — but it has overlooked napping, which is a crucial part of the sleep-wake cycle and carries its own health implications, according to Chenlu Gao, PhD, the lead investigator of the study. Gao told Medscape Medical News, “Our findings suggest that certain patterns of napping could serve as early indicators of declining health.”

Napping for longer and on a more irregular schedule were both associated with a higher risk of mortality. Gao explained, “Longer or more irregular naps may reflect poor nighttime sleep, circadian rhythm disruption, or underlying health conditions such as cardiovascular disease, metabolic disorders, depression, or early neurodegenerative changes.”



Key findings: the three nap red flags

Long naps (>30 minutes)

Folks who napped longer than 30 minutes regularly showed significantly higher mortality risk, tied to metabolic issues like obesity and hypertension. Similar patterns have emerged in prior studies – like a meta-analysis of over 300,000 participants – linking long naps to a 19–30 % higher risk of death and heart disease.

Irregular naps

Unpredictable napping schedules – when nap length varies wildly day to day – also correlated with increased mortality. This inconsistency could disrupt circadian rhythms and mask health issues, potentially worsening metabolic and cardiovascular outcomes.

Midday-heavy napping (11 am – 3 pm)

Surprisingly, those who most often dozed off between late morning and mid-afternoon bore a greater mortality risk, even after adjusting for lifestyle and health factors.



Why does it smell of trouble?

Gao explained that these “dangerous” nap patterns might signal underlying sleep disruptions, like poor night sleep or circadian misalignment, or diseases such as cardiovascular or metabolic disorders.

And this isn't conjecture. A 2022 Harvard Heart Letter involving 360,000 adults found frequent napping tied to a 12 % increased risk of hypertension and a 24% elevated stroke risk.

Likewise, long, irregular naps have been tied to conditions such as high waist circumference, hypertension, insulin resistance, inflammation, and early signs of neurodegenerative decline.

While naps shorter than 30–45 minutes seemed benign – or even beneficial – longer and erratic naps raised red flags. This aligns with the idea that consistency matters, a point supported by emerging research showing sleep regularity (beyond just duration) might strongly predict longevity.


Correlation or causation?

Critically, these are observational links, not proof of causality. Long or irregular naps likely flag health issues rather than cause them. Moreover, nighttime sleep quality, undiagnosed conditions (like sleep apnea or cardiovascular risk factors), and tracking limitations (e.g., misclassified inactivity as naps) all temper interpretations and could lie behind the trends.

However, the sheer scale, objective monitoring, and consistency with past findings lend credibility: nap patterns may function as early biomarkers of declining health.



The ‘nappiness’ strategy

Experts aren’t advising abandoning naps altogether. Instead, they’re recommending: nap smart.

Keep naps short: 15–30 minutes are ideal (“power naps”) – long enough to refresh but short enough to avoid deep sleep inertia.

Stay consistent: Same time each day maintains circadian rhythm.

Nap early: Before around 3 p.m. helps avoid nighttime sleep interference.

Check for underlying issues: Frequent or prolonged daytime dozing – especially with nighttime fatigue – warrants medical review for possible sleep disorders or chronic illness.


In fact, a growing body of sleep research hints that napping patterns may serve as an early biomarker of health decline, beyond just rest. The key takeaway? Not all naps are created equal. The modern nap toolkit is evolving. So, yes to short, strategic breaks. Beware long, erratic snoozes.

Think of it this way: ask not just whether you nap, but how you nap. Sleep may be the gateway to wellness or the SOS signal in disguise – and napping habits are part of that subtle story. So, when the afternoon slump feels deeper than usual, it might be time to check in with your health.

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