Disc bulge: Meaning in a Radiology Report

Disc bulge

Also written as: bulging disc, diffuse disc bulge, annular bulge, disk bulge

A disc bulge means a spinal disc extends slightly past the edges of the vertebrae around a wide part of its rim. It is very common and often painless.

Seen on: MRI, CT

How it reads in a report

L4-L5: There is a mild diffuse disc bulge without significant spinal canal or foraminal stenosis.

What it means

Discs are the cushions between the vertebrae, with a tough outer ring and a softer center. With age, a disc loses water and height, and its outer ring can spread outward, much like a cushion flattening under weight. A bulge is broad and shallow, usually only a few millimeters, and covers a wide part of the disc's edge. It is not counted as a herniation.

When it matters

Bulges are very common, even in people with no back pain, and become more frequent with age. So a bulge may or may not be linked to your symptoms. Doctors look more closely when a bulge narrows the spinal canal or the openings where nerves exit, often together with arthritic joints or a thickened ligament. This matters most when your symptoms fit that level. A bulge alone seldom needs a follow-up scan.

Questions to ask your doctor

Is the bulge narrowing the space around a nerve root or the spinal canal?
Could this bulge explain my symptoms, or is it likely age-related wear?
Is a bulge like this common for someone my age?

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.