The first thing I would check on is how much sleep you're getting, and what quality of sleep. I've heard a lot about people needing less than the standard eight hours, but those people usually take long naps to account for the time they didn't sleep overnight. I can't get up out of bed worth a thing if I haven't slept a full eight hours, or more if I'm behind on sleep, so that's the first thing I would check.
Then, on quality of sleep...do you wake up a lot during the night? Do you remember your dreams often? Do you feel any aches upon waking? You may need to adjust your sleeping posture; your skeleton should sit in a rather natural alignment for the entire night. I would suggest sleeping on your side for this, and your right side at that; sleeping on your right side makes it easier for your heart to pump blood to the majority of your body due to gravity. I use a thick pillow between my legs to keep my legs aligned properly and I used to put a thin pillow beneath my obliques / love handle area to keep my spine aligned. Also, get the right amount of pillow-age underneath your head to ensure that your head is aligned properly as well. I tuck my (top) pillow as close as I can possibly get it to my shoulder and neck so it's supported directly.
Also, are you exercising at all, and more importantly, are you exercising regularly? The human body was designed to go through a regular physical activity program; think back to when humans first came into existence. They weren't driving cars and eating McCrackRocks every day. They were hunting and gathering. Running things down and killing them, walking around picking berries and all this mess. Running away from things trying to eat them. The point is that the body doesn't operate well when it doesn't get everything it needs, be it nutrients, sleep, or exercise. Think about that for a while.
