It does sound, however, like you've had alterations in your normal state of health. Those are always red flags, even if it's just your body can't process the sodium it used to could...
The do bear watching.
Honestly, the causes of pitting edema (I didn't know how to look it up before you named it) are all pretty scary or depressing, depending on which emotion I decide to apply to it. BUT, I don't have any of the ~other~ symptoms of any of the major organ failures they discuss. I don't think I have congestive heart failure, liver, or kidney disease, necessarily.
Rolling around in the back of my mind though are two things... and part of my thinks I shouldn't be posting all this in a public forum, but what the heck...
Liver cancer killed my mom and her brother. But not this young, it came later.... twenty years from now. And it wasn't cirrohsis, it was cancer. BUT, the women in my family did have huge ankles late in life. Moreso my grandma and another aunt (the one that ~hasn't~ gotten cancer) than my mom, though. Mom didn't really get swollen ankles ever. When her liver failed, her retention was all abdominal.
Other things I'm thinking about too, that I don't feel like I am at liberty to discuss, but I want Ramius to see.
Edema (pitting and non-pitting edema) information at MedicineNet.com
I don't see how bear watching is going to help.