Bulge
Very common
What it means
The disc's outer edge extends slightly beyond where it should, broadly rather than at one point.
Significance
Usually none. Extremely common with age and often reported in people with no symptoms.
Cervical disc herniation: what a slipped disc in the neck really is
Discs do not slip. A disc is firmly attached to the bones above and below it, and what actually happens is that part of its soft centre pushes out through, or stretches, the tough outer ring. If that displaced material touches a nerve it can hurt a great deal. If it does not, you may never know it is there.
What you need to know in 30 seconds
Nothing slips. Part of the disc's soft centre displaces outward, and the words on your report describe how far.
Disc bulging is extremely common and usually silent. In one study of people with no symptoms at all, 87.6 per cent had it.
It only matters when it presses on something. Pressing a nerve root causes arm pain; pressing the cord is more serious.
Most symptomatic herniations settle without surgery, and the body often reabsorbs part of the displaced material.
Most happen without an injury. An ordinary movement on an already worn disc is the usual story.
A herniation on a scan is not a diagnosis on its own. It has to match what you feel and what the examination shows.
87.6%
Of people with no neck symptoms had disc bulging on MRI in a study of 1,211 volunteers.
Not a slip
Discs are firmly anchored to the bone. The soft centre displaces; the disc stays put.
Often shrinks
Displaced disc material is frequently reabsorbed by the body over months.
Rarely surgical
Most people with a symptomatic herniation get better without an operation.
WHAT IT IS
A soft centre inside a tough ring
Each disc has a firm outer ring and a softer, gel-like centre that acts as a cushion. A herniation is what happens when that centre pushes outward. How far it goes is what the different terms on your report describe.
1
Normal disc: soft centre held inside a tough outer ring
2
Bulge: the outer rim is displaced broadly and shallowly
3
Protrusion: a focal bump, wider at its base than its tip
4
Extrusion: material through a narrow neck into a wider dome
01
Where it goes decides what it does
A herniation off to one side tends to press a single nerve root, which causes arm pain, tingling or weakness. One that pushes straight backward can press the spinal cord instead, which is cervical myelopathy and a more serious situation.
02
Most are found, not felt
In a study of 1,211 people with no neck symptoms, 87.6 per cent had some form of disc bulging on MRI, and it became more common with age. A finding on a report is only meaningful if it lines up with your symptoms and your examination.
03
The body often clears it up
Displaced disc material is treated by the body as something to be broken down and removed, and follow-up scans often show a herniation has shrunk or disappeared over months. This is a large part of why patience so often works.
DECODING YOUR REPORT
The words a radiologist uses, in plain English
These terms describe how far the disc material has moved, not how much it hurts. A large extrusion can be painless and a small protrusion can be agony, because what matters is whether it is touching a nerve.
Protrusion
Common
What it means
A focal bump at one spot, still contained, with a base wider than the part sticking out.
Significance
Matters if it sits where a nerve runs. Often settles as the inflammation around it calms down.
Extrusion
Less common
What it means
Material has pushed further out through the outer ring, so the part outside is wider than its neck.
Significance
More likely to cause symptoms, but also the type most often reabsorbed by the body over time.
Sequestration
Uncommon
What it means
A fragment has separated completely from the parent disc and sits free in the canal.
Significance
Depends entirely on where the fragment has come to rest and what it is resting against.
WHEN TO ACT SOONER
The signs that change the timeline
Painful is not the same as dangerous. Even severe arm pain from a herniation can usually be given time. These are the exceptions.
1
Weakness that is getting worse
A muscle becoming measurably weaker week to week, rather than pain alone, is the main reason to be seen sooner.
2
Clumsy hands or unsteady walking
This suggests the herniation may be pressing the spinal cord rather than a single nerve root.
3
Symptoms in both arms or the legs
A single nerve root affects one arm. Anything more widespread needs looking at without a long wait.
4
Pain that will not settle at all
Severe pain that has not eased after several weeks of proper non-surgical treatment is worth a specialist opinion.
Seek urgent care
Sudden or rapidly worsening weakness, new clumsiness and unsteadiness affecting both hands, or any change in bladder or bowel control can mean the spinal cord is under pressure. Call 000 or go to your nearest emergency department. GPs with an urgent concern can phone the rooms directly on (07) 3870 3708.
WHAT CAUSES IT
Usually no single dramatic moment
People often search for the injury that caused it. Far more often there is not one, and the disc had already changed quietly over years before the day it started hurting.
01
Age-related change
Discs lose water content and become less elastic with age, which makes the outer ring more likely to give way. This is part of cervical spondylosis.
02
An ordinary movement
Reaching, twisting, or lifting something unremarkable is the commonest trigger. The movement is rarely the real cause; it is the last straw on a disc that was already worn.
03
A genuine injury
A fall, a sporting impact or a car accident can herniate a disc directly. This is the minority of cases but it is the group most likely to come on suddenly.
04
Load and habit over time
Sustained awkward neck positions and heavy repetitive loading add up. Smoking is also associated with faster disc degeneration.
HOW IT IS DIAGNOSED
The examination decides what the scan means
01
History and examination
Where the pain travels, which fingers are affected and which movements are weak point to a specific level before any imaging is done.
02
MRI
The best test for showing disc material, nerves and the space available. It shows what has moved and what it is touching, with no radiation.
03
CT or nerve studies
CT shows bone detail well when that matters. Nerve conduction studies help separate a neck problem from something further down the arm.
Because disc findings are so common in people without symptoms, the useful question is never simply whether you have a herniation. It is whether the herniation on your scan explains the symptoms you actually have. That is a judgement, and it is the part experience contributes most to.
WILL IT GET BETTER?
Usually, and often without anyone operating
This is the part worth holding onto when the pain is at its worst, because the natural course is genuinely favourable.
Most do
Where a herniation is causing nerve pain, more than eight in ten people with acute cervical radiculopathy improve without surgery, most within about eight to twelve weeks. Displaced disc material is also frequently reabsorbed over months, so follow-up scans often look better than the first one. Early treatment is about keeping you comfortable and moving while that happens.
TREATMENT
A ladder, climbed only as far as you need
FIRST
Time and staying active
Most herniations settle over weeks to a few months. Gentle activity, avoiding the positions that flare it, beats resting completely.
ALONGSIDE
Physiotherapy and medication
Targeted physiotherapy plus anti-inflammatory or nerve-specific pain medication carries most people through the worst of it.
SOMETIMES
A targeted injection
An injection placed at the affected nerve can settle stubborn inflammation and buy time for the disc material to be reabsorbed.
ONLY IF NEEDED
Surgery to remove the fragment
Considered for worsening weakness, cord compression, or pain that will not settle. The aim is to take the pressure off.
If surgery is the right step
ACDF
The disc is removed from the front and the level fused. Reliable and long established for taking pressure off a nerve or the cord.
About ACDF ›Disc replacement
The disc is replaced with a mobile artificial one, preserving movement at that level. Suitable for selected patients.
About disc replacement ›Foraminotomy
The nerve's exit is opened from behind to release the root without fusing the level. An option where the anatomy suits.
About foraminotomy ›Which option suits depends on where the material has gone and what it is pressing on. Still weighing it up? Do I need neck surgery? and non-surgical treatment go into more detail.
Discs do not slip, and displaced material is often reabsorbed
A disc is firmly attached to the bones above and below it, so nothing slips. What moves is the soft material inside, which is why herniation describes the problem far better than the word patients are usually given.
COMMON QUESTIONS
The things people ask most
Is a slipped disc the same as a herniated disc?
People mean the same thing, but nothing actually slips. The disc stays attached to the bones above and below it. What moves is the soft material inside, which pushes out through or stretches the tough outer ring.
Can a herniated disc heal on its own?
Often, yes. The body treats displaced disc material as something to break down and remove, and follow-up scans frequently show it has shrunk. Symptoms usually improve well before the scan changes.
My scan shows a bulge. Should I be worried?
Probably not on its own. In a study of 1,211 people with no neck symptoms, 87.6 per cent had disc bulging. A bulge only matters if it explains symptoms you actually have.
How long does the pain last?
Where it is causing nerve pain, most people improve over about six to twelve weeks. Some settle faster and a minority take longer. Weakness that is worsening rather than pain that is slowly easing is the thing to report.
Should I avoid exercise?
Avoid what clearly flares it, but not movement in general. Staying gently active is better than resting completely. A physiotherapist can help you find what is safe to keep doing.
Will I definitely need surgery?
Most people do not. Surgery is considered mainly for weakness that is getting worse, signs the spinal cord is involved, or pain that will not settle despite proper treatment.
RELATED CONDITIONS
Closely connected to this one
Cervical radiculopathy
Neck and arm pain from a pinched nerve root. The commonest consequence of a disc pressing sideways.
Read about radiculopathy ›Cervical myelopathy
Pressure on the spinal cord rather than a single root. More serious, and the reason central herniations get closer attention.
Read about myelopathy ›Cervical spondylosis
Age-related change in the discs and joints that makes a herniation more likely in the first place.
Read about spondylosis ›About this information
This page is general information about the cervical spine. It is not a substitute for an individual assessment and it cannot tell you what is happening in your own neck. Where figures are given, they come from the published research listed below and describe groups of people rather than individuals. Please discuss your own circumstances with your GP or a specialist. More about Dr Tollesson.
References
Abnormal Findings on Magnetic Resonance Images of the Cervical Spines in 1211 Asymptomatic Subjects. Spine, 2015, for the prevalence of disc bulging in people without symptoms.
Cervical Radiculopathy, StatPearls, National Library of Medicine, for the natural history of nerve pain caused by a herniation.
A disc finding on a report is a starting point, not a verdict.
A consultation will tell you what is actually causing your symptoms, whether it needs treating, and what the realistic options are. A GP or specialist referral is needed for a Medicare rebate.