Looking For Cause Of Burning, Stinging Pain In Left Foot,

looking for cause of burning, stinging pain in left foot, primarily upper arch area; swelling and pain have continued for 3 months. No known injury.
Cannot associate level of swelling to pain or activity. Aleve for 3 weeks lessened pain and swelling after 1 day or so, but swelling continued, reduces some overnight, usually worsens throughout the day; occasionally goes almost back to normal for short periods of time. Pain extends into ankle area and radiates up leg. Icing helps temporarily.