I have heard that edema is caused by dehydration. I have also heard that it is caused by congestive heart failure among other things. I guess there could be any number of reasons for it.
I am far from an expert on dry fasting. I am just trying to do some research on it to educate myself. I thought I would post some of my findings. I was happy to see a lot more information than what I could find a few years ago.
My dream is that I will be able to successfully dry fast some day. It looks like it could be a lot more dangerous than water fasting. It would be important to be knowledgeable about it before doing it. It may not be wise for some with certain health issues.
I have heard some testimonies from people who had the difficulty of staying on a water-only fast, but had no problems at all sticking to a dry fast.