I'VE HAD A BUMP ON MY RIGHT HEEL FOR ABOUT

I'VE HAD A BUMP ON MY RIGHT HEEL FOR ABOUT A YEAR, JUST LEFT OF CENTER AND LOW (NOT NEAR ANKLE). IT IS USUALLY SLIGHTLY PAINFUL, ESPECIALLY WHEN I WALK A LOT. TODAY I NOTICED DARK REDNESS ON HALF OF THE BUMP AND NOW IT IS LARGER THEN PREVIOUSLY. I GO BAREFOOT A LOT AND WEAR RUNNING SHOES OR CASUAL SHOES WHEN I GO OUT. WHAT IS THIS THING AND HOW CAN I MAKE IT GO AWAY.