Disc herniation: Meaning in a Radiology Report

Also written as: herniated disc, herniated nucleus pulposus, disc prolapse, disk herniation

Disc herniation means material from a spinal disc has moved past the disc's normal edge in one area. Protrusions and extrusions are types of herniation.

What it means

Each disc has a tough outer ring and a softer, gel-like center. In a herniation, disc material is pushed beyond the disc's normal edge in a limited area, rather than around a wide part of the rim as in a bulge. Reports usually give the type (protrusion or extrusion), the size, and where it points: central, paracentral, foraminal (into a nerve exit) or far lateral (beyond the nerve exit).

When it matters

Herniations are common on MRI in people with no back pain. The finding matters most when it presses on a nerve root that fits your symptoms, such as sciatica down one leg. Most of these symptoms improve over weeks to months, and the herniation itself often shrinks. Doctors compare the level and side with your exam. A repeat scan is usually reserved for pain that does not settle or for new weakness.

Questions to ask your doctor

Is my herniation a protrusion or an extrusion, and how large is it?
Does it touch a nerve root that matches where I feel symptoms?
How likely is it to shrink or improve on its own?

General information, not medical advice. What a finding means for you depends on your symptoms, your history and the images themselves, so talk your results through with a doctor.