Callous's
Everybody gets them, I have had them for as long as I can remember. Recently my fretting hand index finger's callous has been causing a deep pain,,,, as in deep down towards the bone.
 
Any thoughts, ideas??
 
TIA

If it's not just the occurring after a long period of playing, then let a doctor check it out.
 
It's not the kind of thing I would ask in an internet community before seeing a doctor.

I'm inclined to agree with Adriaan; have a doctor take a look.  My guess would be that the callous itself is not what's causing the pain.  I suppose you could try not playing for a week or two and see if that makes a difference.