What Causes Numbness On The Finger Tips And Hand?

I have had numbness in my middle two finger tips for some time; then the symptoms went into my hand (right one) and for the past two weeks it has been almost impossible to sleep. I have tried a heating pad, an ice pack and seen my internist who said it could be a pinched nerve in my neck. I have spinal stenosis which has not been a problem for some time.. I have had discomfort in my mid spine and about two weeks ago applied a cream that relieved the pain and also the small raise in my spine has returned to normal, Would you please share your thought as to what my problem could be. I was unable to sleep tonight so went to my computer for possible enlightenment