The first component of disc degeneration or disease is the thinning of the disc. It usually means abnormal position or motion has been present at that site for some time. This amount of degeneration can cause no symptoms but due to the nerve roots that exit at that site it can cause neck pain, decreased range of motion, headache, radiating pain or numbness into the arm. Though symptoms may not be present the nerve can be affected at a subclinical level and as degeneration increases over time symptoms may appear.