I get leg and foot cramps, but don t think they are related to dehydration because they often happen when I have drank a lot of water right before going to bed. Is there another reason these could happen? They are much more painful than the charley horse type cramps I got when I was younger and once they begin it is hard to get them to stop. This only happens when I am trying to go to sleep, or am already sleeping. Getting up and walking around usually helps, but as soon as I lay back down they return.