For No Explained Reason, The Top And Side Of My

For no explained reason, the top and side of my left foot began to ache and swell last night... I have gout but have not had a flair up since 2013. The pain is at the surface even though it feels deep because it throbs. I eat a clean diet for the most part and exercise at let 3-4 times a week. I have no idea what caused this...

Thank you