Suggest Cure For Pitting Edema In The Legs

I have had problems with pitting edema in my legs, with the Left leg being extremely bad sometimes swelling 2 or 3 times bigger than the right leg. Over the years different doctors seem very concerned, run a few tests, then never say anything. Even when I seen a cardiologist a year ago he was extremely concerned and then even more so as he was checking the pulse in the left leg and foot with a real concern on his face and ran some tests. I am assuming if they don't say something is wrong there is nothing wrong, but is that true? Could there be a problem they don't want to tell me or is there a problem but they don't really know what it is?