What Causes Chronic Swelling And Pain In Ankle?

I have a pain in my left angle that I first encountered in October. I cannot wear heels fir the back of my ankle hurts. It's a radiating pain that is intense when I come down the stairs and any pressure is applied to the area. I have seen my doctor 4times over the months since feeling the pain, at first he took me off the statin drug and did blood work where the CPK was elevated. Since then I noticed some swelling in the ankle with pain. I saw a Podiatrist and he said there needs to be a Doppler test to rule out DVT. I am really concerned about this. I am having the test done and I also requested a MRI. My question is is there any other tests I should be doing?? And what could these symptoms mean???