Discs separate the bones (vertebrae) of the spine and provide a cushioning effect. The disc is comprised of a soft inner center (the nucleus pulposus) , surrounded by a tough outer shell of fibrous tissue (the annulus), much like a jelly donut. Many factors can contribute to a sudden or gradual breakdown of the disc, resulting in bulging or even herniation of the disc. Disc herniation can produce both localized and referred pain, and can affect the nerves of the arms or legs. Symptoms can include numbness in the extremity and even weakness if the disc is irritating the nerve.

Neck pain has many causes, including:

  1. Côté P, Cassidy D, Carroll L. The Saskatchewan health and back pain survey: the prevalence of neck pain and related disability in Saskatchewan adults. Spine 1998;23:1689–1698.
  2. Côté P, Cassidy D, Carroll L, Kristman V. The annual incidence and course of neck pain in the general population: a population-based cohort study. Pain 2004: 112:267-273.