What Causes Numbness On The Bottom Of Feet?

I have numbness on the bottom of my feet, I am not a diabetic - have heart deasease & had Chemo theraphy 8 yrs. ago. Please Help shed some light on this problem.Thank You Brenda P.S. I can not afford to pay for this question, not now. So I quess I will not get my answer, I wish I knew there was a fee, I would have not started it. Sorry