For some reason, I always feel tired. Even though I often wake up in the middle of the night, I usually get at least 8 hours of sleep, if not more. However, I rarely feel refreshed in the morning. For some reason, this sense of fatigue is even more acute at work, and at times it makes it very difficult to concentrate.

I'm pretty sure that this fatigue is partly due to stress and other related issues, but that may not be the sole reason. Has anyone had this before, and how have they dealt with it?