A small-sample study examining the cervical spine in symptom-free volunteers found focal disc protrusions in 50% of participants, suggesting that a considerable part of the population might have focal herniated discs in their cervical region that do not cause noticeable symptoms.
A limited study on asymptomatic individuals revealed that 50% had focal disc protrusion in their cervical spine, indicating that many people may have herniated discs in this area without experiencing any symptoms.