I doubt this is an ME/CFS symptom, but who knows - has anyone else had this? It is on the sole of my foot, on the ball. I went to my GP and he said he isnt sure what it is. Says it could be a cyst, or something. Doesnt think it is cancerous. It feels quite hard to me, not as hard as bone, but not too soft either. I noticed it a week ago when I was walking barefoot. I dont walk much, or exercise, which means i dont wear shoes much either, as mostly sat down. That perhaps rules out a few things. GP says to come back in several months if still there.