There is a bone bulge at the back of the neck, besides the normal physiological structure, it may also be caused by cervical spondylosis, cervical spine old injury and so on. 1. Normal physiological structure: Due to the different growth and development of each person, there are differences in the degree of concavity and convexity, and the spinous process of the second cervical vertebrae will be more prominent in some people than in others, so there is no need to deal with it if there is no discomfort. 2. Cervical spondylosis: such as prolonged head down, watching computer, poor sitting posture, etc. can cause cervical spondylosis or cervical vertebrae small joints disorders, the back of the neck will be protruding phenomenon. 3. Old cervical spine injury: If there are some cervical spine fractures and dislocations, there may be localized bony bumps after recovery. There may be other reasons for a bone protrusion at the back of the neck, so it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and carry out standardized treatment under the guidance of the doctor.