Head and neck pain, no recent injury - causes?

Musculoskeletal: 30's person w. Head ; neck pain absent injury perplexed about cause. In this age group common to wake w. Unilateral neck pain especially, to my observation, in fall ; spring when weather changes. My consideration is that sleeping posture ; cool room air induce muscle spasm. If heat ; rest do not resolve in a week or so see a doctor. Massage is oft helpful. This can be a true "pain in the neck".

Muscles and Nerves: Typically either side of neck and head are provided sensation by nerves that supply them exiting out of the neck and head. Muscles also lying in that area may be the issue as well. If there is a history of neck pain that should be evaluated since there could be arthritis, nerve impingement or herniated disks involved. History of head trauma could also result in this pain as well.