A bulging disc forms when the soft, spongy center of the disk (nucleus pulposus) pushes out and puts pressure on the outer surrounding fibrous ligament (annulus fibrosis). Unlike a herniated disc, the bulging disc still contains the nucleus material.
Bulging most often happens as the body ages and the intervertebral discs degenerate. Having a bulging disc is not necessarily a serious concern, and it may or may not be a source of back pain and/or leg pain.
Disc herniation (Ruptured Disc/Prolapsed Disc/Slipped Disc) is a rupture of fibrocartilagenous material (annulus fibrosis) that surrounds the intervertebral disc. This rupture involves the release of the disc’s center portion containing a gelatinous substance (nucleus pulposus). Pressure from the vertebrae above and below may cause the nucleus pulposus to be forced outward, placing pressure on the spinal nerves, and may cause considerable pain and damage to the nerves. This is called herniated nucleus pulposus (slipped disc, prolapsed disc or ruptured disc).
This condition can occur in both the cervical spine (neck) and lumbar spine (low back). It is more common in the lumbar spine (low back). In the cervical spine (neck), the herniated nucleus pulposus may cause neck pain and/or upper extremity symptoms. In the lumbar spine (low back), it may cause low back and/or lower extremity symptoms. It can rarely occur in the thoracic spine (upper/middle back), creating (radiating) pain to the chest or belly, heart, lung, GI, kidney as well as other musculoskeletal causes and should be evaluated.