Poor posture while sleeping, sitting on computers or jobs for a long time, uneven bed, exposure of back
to cold air while sleeping
can cause a discomfort for a few days. Take a multivitamin, plenty of fluids, and an OTC analgesic. Apply a local analgesic and apply a heating pad and see if it helps. If this does not help, consult a neurologist. A MRI of the spine will be definitely required. The treatment is to remove the compression.