Post.neck pain for 2months. one day it hurts on lt side(no pain on rt) next day on rt side(no pain on lt) what could this be?how to treat?

Neck pain: Sprain, strain, or referred disk pain. Check with your pcp or neck doctor.

Disk or nerve : The symptoms you describe can be from one of a few causes, but most likely from an intervertebral disc tear or protrusion. These can be very painful and can irritate the nerve roots as they exit the neck and cause pain in the shoulder, arm, or scapula region. Older folks can have pain from the small facet joints in the spine. Muscle spasms can also cause pain, often from poor posture or trauma.