Pain, numbness and tingling in arm

For a few months now I have had severe throbbing pain in my right aremand milder in my left.  It wakes me up at night.  It hurts constantly.  I have already had carpal tunnel and shoulder (arthritis) surgery on both hands and shoulders.  I just had an MRI done of my neck and was told there were no buldges or disk problems.  Everything looks great.  I am being referred to a Nuerologist.  Do you have any idea what could be going on?  I am in construction work.  I do have long physical days.