I had a grade 3 ankle sprain just over a yr ago and still have dull pain and bruising/discoloration, what should I do?
See a doctor. A podiatrist or orthopod should be consulted to see if there is any residual damage caused by the sprains. The discoloration could be staining of the skin from "heme" escaping from the blood vessels during the trauma.
May need an MRI. Limit your activity for now and have it re-evaluated.
See an orthopod. True grade 3 injuries continue to cause problems usually for one of two reasons. Either there is an associated injury (talar dome injury, non-healed lateral ankle ligaments, scar tissue in the ankle gutter, etc.) or the more common reason is incomplete rehabilitation of the ankle with decrease proprioception and achilles tendon tightness. Get the diagnosis right and the treatment will follow.