Herniated nucleus pulposus is a condition in which part or all of the soft, gelatinous central portion of an intervertebral disk is forced through a weakened part of the disk, resulting in back pain and nerve root irritation.
Update Date 5/9/2015
Updated by: C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.