I Have Been Experiencing Swollen Ankles And Legs For Quite

I have been experiencing swollen ankles and legs for quite some time and have been under Doctor's care, therfore have had all of the tests and none of the tests showed any problems. I am taking two different water pills and wear support stockings. Nobody can tell me what is causing this. All tests including heart, kidneys,liver and blood tests are perfect. I have never smoked. So HLP>