I Have Been Plaqued With Swollen Legs And Ankles For

i have been plaqued with swollen legs and ankles for years and have taken different fluid pills that only seem to mask the problem. I had a steriod shot for iching and like overnight my feet and legs went down and i can see my ankles and my shin bones and lets not forget the relief of pain and soreness too. My question is what in that shot did what the fluid pills did not touch?