https://www.pennmedicine.org/updates/blogs/musculoskeletal-and-rheumatology/2018/november/bulging-disc-vs-herniated-disc

Medical News Today has strict sourcing guidelines and draws only from peer-reviewed studies, academic research institutions, and medical journals and associations. We avoid using tertiary references. We link primary sources — including studies, scientific references, and statistics — within each article and also list them in the resources section at the bottom of our articles. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.A bulging disk occurs when the inner, jelly like portion of the disks between the bones in the spine bulge out through a tear in the outer (annulus) portion of the disk. Each disk contains a tough outer layer with gel in the middle. This gel may lose its flexibility and become rigid with age.