My Son Is A Type 1 Diabetic Since Age 13.

My son is a Type 1 diabetic since age 13. Now age 29. Lately has been feeling like he is walking on a "rock" and can feel hard lump (very painful) in his foot. Says it's definitely not a bunion. I'm thinking peripheral neuropathy maybe, or a stress fracture (he has been doing a lot of walking lately, but not a runner/jogger). Thank you for your help.