How common is it for a 42 female to have canal stenosis cervical radiculopathy nerve root impingement herniated discs forimanal narrowing?

I would say that. for most people, by the time we reach 40, we are going to find something "wrong" in their spine, degenerative changes, etc. Wear and tear is part of life. However, whenever these changes lead to radiculopathy, this is a different type of pain.