Currently I am sleeping about 6 hours a day (or a bit less than that): from midnight to around 6 AM. I usually not feel sleepy after I wake up (and the neighborhood of where I just moved into is quite noisy every morning so that it is rather difficult for me to go back to sleep) so I usually get up right away.

I am afraid that I might not have had enough sleep each night (although I do not feel that much tired during the day) and that it might be harmful to me (in the long term) to sleep only around 6 hours a day. (Not sure if this is a relevant information: my age is 26.)

So is it really harmful for health (in any way) to sleep just around 6 hours (or less) a day? Is there any indication to tell if an individual gets enough sleep each day?

  • Donald Trump sleeps less than you, Modi, the Indian Prime minister sleeps even less. And we can read here: "McChrystal is reported to run 7 to 8 miles (11 to 13 km) daily, eat one meal per day, and sleep four hours a night." – Count Iblis Mar 31 '17 at 7:20
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    Those are anecdotes of individuals, and say nothing about their actual health. Instead, look at trustworthy resources on the topic. – DoctorWhom Apr 1 '17 at 2:54
  • @DoctorWhom That's right, but this also depends on what you want to get out of your life. If Trump were to collapse and die tomorrow, he'll still have lived for quite some time in reasonable health. Also you have to take into account that 8 hours sleep (which I personally do stick to) is going to cut a third out of your effective lifespan, while 4 hours sleep as Thatcher managed to do, amounts to only a sixth of your lifetime spent in bed. By the time I'm as old as Thatcher when she died, it would be misleading to say that I've outlived her. – Count Iblis Apr 1 '17 at 20:31
  • @CountIblis Yes some people do that, at whatever cost to their health. But his question isn't whether it can be done, he asked if it was harmful to health. And there is plenty of research on it. There are reasons why medical residents have limitations on work hours. There are varying degrees of sleep deprivation and individual differences. But some of those mentioned may be exceptions to the rule. I may be able to manage a few nights of 4 hours like that, but my mind isn't as sharp and my time awake isn't as productive or energized as when I get 7-8 hours. – DoctorWhom Apr 1 '17 at 23:31
  • It's one thing to mention individuals who successfully deviate from the norm. It's another to say anyone can do it. Being tired isn't always a symptom of sleep deprivation. That is why I recommended reading about it, not saying "some people do it and are seemingly okay." Also, for Thatcher or Trump for that matter, what defines whether one "outlives" another person? Hours awake? Total years left as a living human? Quality, physical health and personal satisfaction during fewer hours? That's a great philosophical question we can take to Philosophy SE :) – DoctorWhom Apr 1 '17 at 23:35