Pain in the cervical region of the spine can be caused by a number of factors. Excessive or traumatic movement of the neck, for example whiplash resulting from a car accident, can cause quite severe pain. More long term, chronic issues with the neck include arthritis, herniated (slipped) disc and damage to the vertebrae (spondylitis / spondylosis).
The severity of your injury will determine the treatment methods afforded to you, which is why a professional diagnosis is essential. Following trauma paramedics will offer neck support to minimise the risk of further injury being caused before a full x-ray or scan can help diagnose the extent of the injury. For less severe conditions such as stiffness or through wear and tear a neck collar may be used which offers comfort as well as restricting movement.