What kills you is not a lack of sleep, but...?


Sleep Hours

What do you know and what don't you know?

Over the years, I have always heard people complain that how "terrible" it is to lose sleep time due to stress. Many people, including myself, tend to sleep in or take naps during weekends to make up for the lost sleep time. If you work in a Tech company in Bay Area, the level of stress may really put some challenges into your ability to relax and enjoy a high quality of sleep.

Some of my clients worry so much about negative health consequences after not being able to fall asleep easily or stay asleep the whole night.

Then here is the question:


Will lack of sleep threaten our lives and health?

If we try to sleep a lot in order to make up for it, will that be helpful?


One recent research published in 2016 found that short sleep duration is not associated with high mortality rate. However, habitual long sleep duration actually has an association with "all-cause mortality." 

The research team led by Dr. Aurora explored the health data from 5784 participants over an average of a 10-year period. They compared mortality rate among people who sleep for less than 7 hours per night (short sleep group), between 7 to 8 hours per night (normal sleep group), and for 9 hours or more per night (long sleep group). They summarized three important findings:

  • Consistent normal sleep duration (7-8h/night) is associated with the lowest mortality risk, in comparison to long or short sleep duration.

  • Habitually long sleep duration (9h or more) is associated with increased "all-cause mortality."

  • Change of sleep duration (from normal to long, or from long to short), is also associated with increased all-cause mortality.

Someone may criticize and say: "it is just a 5000-people sample." There is actually another research in 2016 came up with similar conclusions.

Researchers conducted a meta-analysis including 35 articles involving 1.5 million participants and found that compared to 7-hour sleep per day, the mortality increases as you sleep more and more, but not when you sleep less. For example, when you sleep 4 hours each day versus 8 hours each day, the mortality rates are both 1.07 times of those who sleeps 7 hours per day. However, when you sleep 11 hours per day, your mortality rate almost doubles than those who only sleeps about 7 hours per day.

The relationship between sleep and health is an important topic. We all need to be smart about our sleep!




Shen, X., Wu, Y., & Zhang, D. (2016). Nighttime sleep duration, 24-hour sleep duration and risk of all-cause mortality among adults: a meta-analysis of prospective cohort studies. Scientific reports6.

Aurora, R. N., Kim, J. S., Crainiceanu, C., O'hearn, D., & Punjabi, N. M. (2016). Habitual sleep duration and all-cause mortality in a general community sample. Sleep39(11), 1903-1909.

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