Vitality is a measure of how tired you are. The higher the percentage,
the less tired you feel. The more active you are, the quicker you drop in
vitality. If your vitality gets very low, it will begin to affect you
negatively and may even cause you to fall asleep against your will.
In order to regain your vitality, you can either sleep, meditate, or
refresh yourself with the refresh spell. Resting will help but not much.
There is also a rumor that the spell energy drain may help you recover
vitality as well.
See Also: REFRESH SLEEP