Apart from the symptoms - I would also ask, what might have changed at that time or before? Sometimes the body takes awhile to show us there is a problem.

Or any past injuries or accidents in the upper body areas?

repetitive jobs or hobbies?
past whiplash?
sports injuries?
posture changes - head forward, shoulders forward or hunched/rolled

If you can connect these sx with a time or injury it will make more sense, but if none of those things connect then other conditions need to be looked at.