Neck pain. Posterior view of the hand of a woman holding the side of her aching neck. Neck pain and stiffness may be caused by spasm of muscles in the neck and spine. More serious is a whiplash injury of the neck in which soft tissues, ligaments and spinal joints, are injured due to the neck being suddenly and forcibly bent. Neck fractures and slipped disc may also cause considerable neck pain. Treatments of milder forms of neck pain include use of painkilling drugs and massage.