Sleep: Not Too Little, Not Too Much

Craig Stoltz Health Guide
  • News reports about a study presented at a sleep conference suggest that the window for a healthy amount of sleep may be pretty small--and that leaning too far outside that window can be dangerous. This may be true--or not. Let's take a careful look.


    Bottom line first


    Changing from getting around 7 hours of sleep to less than 5 hours or more than 8 hours of sleep per night can increase risk of death. Consistently maintaining about 7 hours daily appears to be ideal.


    This study in 50 words or less


    In a large group of Britons, researchers found dropping from around 7 to 5 hours a night over 5 years was linked to a doubling of death rates from cardiovascular disease. Those who increased sleep to over 8 hours also had twice the death risk, but not necessarily from heart disease.

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    Yes, but. . .


    Big caveat here: The risks were found in those who over the five-year period shifted from sleeping around 7 hours a night to either higher or lower amounts--not those who consistently slept lower or higher amounts over the period.


    In other words, change in sleep patterns over a 5-year period is the factor being measured here, not total amount of sleep one may consistently get.


    Therefore, the current report does not connect consistent 5-hour or 8-hours-plus sleep to higher death rates. Future analysis may--or may not--bear this out.


    Sleep data were based on two self-reports about 5 years apart--not an entirely reliable measure of sleep amounts.


    The report is not yet published, but is expected to appear soon in the journal Sleep


    So what are you going to do about it?


    • Much research has connected too little sleep to health problems like high blood pressure and cardiovascular disease, so this study is a good reminder of the potential health risks of poor sleep.
    • Many sleep specialists use a more personalized measure of what an individual's "right" amount of sleep is. For most people, 7 to 8 hours is considered within a healthy range. But if you think you may have sleep problems, check with your doctor before concluding that getting (say) more than 8 hours of sleep per day is risky.
    • Wondering if you have a sleep problem? A simple (if crude) eight-question test on our site can help you self-assess your sleep status.


    Learn more 


    Our sleep disorder specialist, Dr. Allen Blaivas, has an excellent SharePost on the health risks of sleep disorders.


    Our MySleepCentral site is full of insights you may find useful from experts and patients.




Published On: September 26, 2007