Does lack of sleep actually harm the body?

Well, I have been up since 5:30 and I'm not sure that I agree with the quote below. I got up because I simply couldn't sleep. Now I'm dragging around as if I am not sure if I will make it until lunch!  I wonder what studies have been done regarding just how well you can perform when you haven't the normal number of hours that you body is used to??

If you can't sleep, then get up and do something instead of lying there worrying. It's the worry that gets you, not the lack of sleep.

Dale Carnegie 

**Stop by every hour to find at least one new quote posted!!