Disc Bulge, Herniation or Prolapse: What’s the Difference?
If you’ve read a spinal scan report, you may have come across terms such as disc bulge, herniation, protrusion, extrusion or sequestration. They can sound alarming, especially when you’re already in pain.
These words describe how a disc looks and where its material has moved. They don’t, on their own, tell us how much pain you should have or which treatment you need.
What is a spinal disc?
Discs sit between the bones of your spine. They help absorb load and allow movement. Each has a tough outer layer (annulus fibrosus) surrounding a softer centre (nucleus pulposus).
When disc tissue extends beyond its usual boundaries, different terms describe its shape and whether it remains attached to the original disc.
Injuries to discs can occur at any level of the spine, but are most common in the low back and the lower neck. Lumbar disc injuries sometimes cause leg symptoms, like sciatica. Cervical disc injuries can cause weakness or numbness into the arm and hand.
Disc bulge: a broader change
A disc bulge occurs when a broad area of the disc extends beyond its normal edges.
Think of a cushion spreading outward when compressed. A bulge is technically different from a herniation, and it does not necessarily progress into one.
Disc herniation: a localised change
A disc herniation occurs when disc material extends beyond its normal boundaries in a more localised area.
“Herniation” is an umbrella term that includes two main shapes: protrusion and extrusion.
- Protrusion: The displaced material has a broad base, like a small mound.
- Extrusion: The displaced portion is wider than its attachment in at least one view on the scan, or is no longer connected to the original disc.
Disc sequestration: a detached fragment
A sequestration is a type of extrusion where a piece of disc material has completely separated from the original disc. It is sometimes called a free fragment.
These distinctions follow established spine and radiology terminology.
What does this mean for your care?
These terms are not a ladder of worsening severity. A scan finding alone cannot establish the cause of your pain or determine whether you need surgery.
What matters is how the finding relates to your symptoms, whether nearby nerves are affected, and what your clinical examination shows.
The aim of an assessment is to put the scan into context—so you understand what it means for you and can make informed decisions about your care.
Non Surgical Spinal Decompression
Spine MT-Core is the latest in Non-Surgical Spinal Decompression technology. It uses a motorised traction system that gently cycles the spine through targeted tension and release phases. This creates a vacuum effect within the disc, drawing in fluid, oxygen, and nutrients to help promote natural repair and reduce disc bulge pressure on sensitive nerves.
At Simply Health and Melbourne Disc Clinic, we incorporate this into a structured care plan alongside appropriate exercise and practical advice. A thorough assessment helps determine whether this approach is suitable for your condition and goals.