Why too little sleep might kill you — and why your guess about sleep might be wrong
Association of Objective and Self-Reported Sleep Duration With All-Cause and Cardiovascular Disease Mortality: A Community-Based Study.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
People who slept 10+ hours objectively had no increased mortality risk—yet those who said they slept >8 hours did.
Common belief: sleeping too long is unhealthy. This study proves the risk isn’t from long sleep—it’s from the illness causing you to sleep long.
Practical Takeaways
If you consistently sleep ≤5 hours, prioritize fixing it—this is a major mortality risk factor.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
People who slept 10+ hours objectively had no increased mortality risk—yet those who said they slept >8 hours did.
Common belief: sleeping too long is unhealthy. This study proves the risk isn’t from long sleep—it’s from the illness causing you to sleep long.
Practical Takeaways
If you consistently sleep ≤5 hours, prioritize fixing it—this is a major mortality risk factor.
Publication
Journal
Journal of the American Heart Association
Year
2023
Authors
Binbin Zhao, Yuxuan Meng, Xiaoying Jin, Wenyu Xi, Qingyan Ma, Jian Yang, Xiancang Ma, B. Yan
Related Content
Claims (6)
If you sleep 8 to 9 hours every night, you’re less likely to have heart problems later on.
People who sleep 5 hours or less each night are more likely to die sooner from any cause or from heart problems than those who sleep 7 to 8 hours, according to sleep measurements taken in labs.
People who sleep too little (4 hours or less) or too much (more than 8 hours) tend to have a higher risk of dying from any cause or heart disease, while those who sleep 7 to 8 hours have the lowest risk—this might mean that how long you think you slept is more about your health problems or poor sleep quality than how well you actually rested.
People often think they slept more or less than they actually did, so when they fill out sleep surveys, their answers don’t match what machines measure — making those surveys less trustworthy for big health studies.
People who say they sleep too little or too much are more likely to die from heart problems, but only those who actually sleep too little (measured by devices) show a clear link—so sleeping a lot might just mean you’re sick or your sleep is bad, not that you’re sleeping too much.