I think a sleep study like sarasweets suggests might be a good idea as is any sort of reading/studying about sleep. I'm almost 70 and recently learned we all wake 3-5 times a night so "continuous" sleep is not something one needs but quality of the 7-8 hours most people need. We should go through the stages and then wake; the reason some people think they don't wake is because they "forget" (like some people never remember dreaming), just roll over and start on Stage 1 again. I had been puzzled because I was getting 2-4 hours at a time, two or three times between going to bed and getting up and it was adding up to about 8 hours sleep and I wasn't tired/didn't nap or anything during the day and thought that odd because sometimes I'd be up in the middle of the night for a couple hours. Turns out that's okay.

Which leads me to the biggest thing I recently learned. If you think you are not sleeping well, guess what? You won't sleep well. Once I understood about sleep and my particular pattern (at this time -- I pretty much slept "all night" until about my 50's :-) I quit stressing/worrying about it and relaxed and now just go-with-the-flow; stress/worry about other things instead