i'm on advair and it seemed like i was getting cramps somewhere on my body day and night and they were getting severe. i was wondering if i should blame the advair (didn't want to as doing so well on it). i read where being dehydrated could cause cramping and then i realized that tho i drink water constantly, i really only take a couple of sips at a time. so i made myself take 5 swallows every time i thought of it and every time i woke up at night (sometimes 2-3 times a night). to my amazement i havent had one cramp in three days. it was as simple as that. so if someone else is having a problem with cramps give water a try.