What Causes Dizziness Post Foot Surgery?

I feel like I have a virus and am taking Advil 3 tabs twice a day to keep my soreness in check and had foot surgery two plus weeks ago. Not feeling well, but my main concern is I m a little spacey and definitely am lightheaded and have been for the last 14 days or so. I can handle the pain, but the dizziness is driving me crazy. Do I have to just ride this out ? Any ideas?