Suggest Treatment For Swelling In Ankles And Calf Muscles

I am 28 year old, female. Since June 2010, I have been having swelling in my ankles & calf muscles towards end of the day. All my chest, kidney and other tests came out normal. Doctor said it is anaemia, serum ferritin was 29.6ng/ml (LOW) but Haemoglobin 11.5gms%.Trace of protein in urine always present. Urinary proteins 24 hrs 125mg. serum urea 16mg/dl . serum protein 7.3g/dl. After taking iron supplements the condition improves but then again it reappears. All ankle swelling disappeared completely from Jan to Feb 2011 for two months & then reappeared again this month. Why does this swelling reappear? Is it related to anaemia or kidney disease?