Hello there,
I am not sure what causes it. I am a sufferer of regular edema, and pretibial myxedema. I am on a strong diuretic- supposedly to control one of the two-to no avail. Everytime I have to go to the ER the first thing they do is check my heart. So please take that into consideration.
Sorry, not much help. Hopefully someone will have more scientific (medical) explanation that will benefit us both..
Buttamama