I am a 24 yr old woman who has had recurrent edema in my lower legs, ankles and feet for as long as I can remember. I am slightly over weight and have been most of my life, however, I lost over 60 lbs two years ago (I was 180). Recently my edema started flairing up again leaving my legs very swollen and sore. There seems to be no specific cause as it comes and goes. With my recent about I gain almost 30 lbs ( Im now 207!) in the last 2.5 months and nothing seems to make it better, even when I elevate my legs it doesn't subside. Do you think this is a thyroid condition or something else? Also my grandma mother and two of my aunts also have edema is it hereditary?

What does your doctor say? Certain blood pressure medications cause some people to develop edema in their legs. Poor liver function can cause it too but it's unlikely that that is going on. Present your case to a medical professional. Tell them about the edema that seems to run in your family.

Do you happen to have kidney problems?

I am going through the same thing and mine is due to my kidneys. You really need to go to the doc and get some blood and urine work up done.
I also have RA which could be the cause - the first time it happened to me I was on Celebrex for two weeks - I looked like I had elephant legs and had gained 30 lbs of water weight.