So it seems many people have just given up completely on the idea of getting enough sleep every night, and have resigned themselves to being tired all the time. And some of those people get a false sense of "getting used to it" when they start to feel less tired and think they've adjusted. But the truth is that not only are these people losing out on sleep, but they're losing the ability to catch up on sleep as well. When only deprived of sleep for one night at at time the body is "extra tired" the following day and sleeps longer or deeper to make up the difference. But when the body is deprived of sleep on a regular and chronic basis it loses the ability to trigger a "make up session" and won't necessarily feel any more tired than normal -- even though the body technically needs more sleep. The body generally suffers all the same negative side-effects of sleep deprivation, only without the warning signs.

So if you think you've "adjusted" to only a few hours of sleep you are probably fooling yourself -- for the best health we all need 7-8 hours a night!