My face is swollen in the mornings (used to be once in a while, now it iseems to be every morning). Somewhere I read that the fluids in your body "migrate" when you're asleep because you are in a horizontal position ( I guess it sloshes up from our feet to our faces/hands).
My swelling goes away in about an hour too. Not sure what causes it. Doesn't seem to be related to food, water intake, or time of the month.
Wish I knew