Disc bulge or wear seen by chance on a spine scan

What the report words mean

Disc degeneration. The soft discs between the bones of the spine break down over time and lose some of their cushioning. (MedlinePlus) Reports may say "disc signal loss" (a darker, drier disc on MRI, sometimes called a "black disc") or "disc height loss". (Brinjikji 2015)
Disc bulge or protrusion. The edge of a disc extends beyond the bones above and below it. A protrusion is a more focal bulge. (Brinjikji 2015) A herniated disk is one where the soft centre leaks out through a tear. (MedlinePlus)
Annular fissure. A small tear in the outer ring of a disc, also seen in people with no pain. (Brinjikji 2015)
Facet degeneration or arthropathy. Wear of the small joints at the back of the spine. (Brinjikji 2015)
Spondylolisthesis. One bone of the spine has slipped slightly forward on the one below. (Brinjikji 2015)
Spondylosis. A general word for wear of the spine with age. The NHS says, for the neck, that it is a normal part of ageing and many people have no symptoms. (NHS neck)

How common it is in people with no back pain, by age

A review of 33 studies (3,110 people with no history of back pain, almost all scanned by MRI) estimated these rates by age. (Brinjikji 2015)

Share of people with no back pain who show each finding, by age
Finding	20	40	60	80
Disc degeneration	37%	68%	88%	96%
Disc signal loss	17%	54%	86%	97%
Disc height loss	24%	45%	67%	84%
Disc bulge	30%	50%	69%	84%
Disc protrusion	29%	33%	38%	43%
Annular fissure	19%	22%	25%	29%
Facet degeneration	4%	18%	50%	83%
Spondylolisthesis	3%	8%	23%	50%

The authors say many of these features are likely part of normal ageing and not linked to pain, and that when they are seen by chance they should usually be read as age-related changes. They also say the findings must be read with the person's symptoms and examination. (Brinjikji 2015)

When it matters

The scan alone does not decide. A herniated disk is diagnosed with a physical exam and, sometimes, imaging. (MedlinePlus) NICE says imaging should not be offered routinely for low back pain outside specialist care, and in specialist care only if the result is likely to change what is done. (NICE NG59)
Seeing a GP. The NHS says to see a GP for back pain that does not improve after a few weeks, stops you doing day-to-day things, comes with weight loss without trying, a lump or swelling or a change in the shape of your back, does not improve with rest or is worse at night, is worse when sneezing, coughing or pooing, or is between the shoulders. (NHS back pain)
Neck findings. For the neck, the NHS says to see a GP for neck pain or stiffness that does not go away after a few weeks or is worse when you move. (NHS neck)
Worry is real. See after an abnormal screening result.

The NHS says to ask for an urgent GP appointment or get help from NHS 111 (your local urgent care line elsewhere) if you have back pain and feel hot, cold, shivery or generally unwell, or the pain is severe and starts suddenly or gets worse quickly. It says to call 999 or go to A&E (your local emergency number elsewhere) for back pain with pain, tingling, weakness or numbness in both legs, loss of feeling around the genitals or anus, changes in bladder or bowels, changes in sexual feeling or function, chest pain, or pain after a serious accident. (NHS back pain) For the neck, it lists heaviness or weakness in the arms or legs, pins and needles in an arm with neck or arm pain, and pain between the shoulder blades as reasons for urgent help, and new problems walking, loss of bladder or bowel control or a sudden lack of co-ordination as reasons to call 999. (NHS neck)

Other things a scan may show

The same scan may mention other chance findings, each with its own page: low bone density seen on CT, a bone spot found by chance and, on a head scan, brain shrinkage (atrophy).

Who it applies to

Adults told that a spine MRI, CT or X-ray, or a scan of another body part that included the spine, shows disc or wear changes. Children, people already being seen for spine problems, and a scan done because of back or neck symptoms are outside this page.

Routine age-based screening

A spine finding on a scan does not replace the routine screenings for your age, such as bone density testing. See screenings by age and gender.

Where they differ:

Normal ageing or a cause of pain. The review of people with no back pain says these findings are usually normal age-related changes when seen by chance. (Brinjikji 2015) A second review by the same group found disc bulges, degeneration, protrusions and some other findings more often in people aged 50 or younger with back pain than in people without, so in younger adults they may matter more. (Brinjikji meta-analysis 2015)
Whether to scan at all. NICE advises against routine imaging for low back pain outside specialist care. (NICE NG59) The review authors note that the studies used different words and did not grade severity, so people with pain may have more severe changes than the rates above suggest. (Brinjikji 2015)

Your doctor decides what your result means for you.

Questions people ask

Is a disc bulge on an MRI normal?

It is common in people with no back pain. A review of 33 studies of people with no history of back pain estimated a disc bulge in 30% of 20-year-olds, 50% of 40-year-olds, 69% of 60-year-olds and 84% of 80-year-olds. (Brinjikji 2015)

What does disc degeneration mean on a scan report?

It describes discs that have dried out, lost height or changed shape over time. The same review estimated it in 37% of people aged 20 and 96% of people aged 80 with no back pain, and its authors say many of these features are likely part of normal ageing. (Brinjikji 2015)

Does a disc bulge cause back pain?

Not always. Many people with a bulge have no pain. A second review found disc bulges and some other findings more often in people aged 50 or younger with back pain than in those without, so the scan is read together with your symptoms and an examination. Your doctor decides what your result means for you. (Brinjikji 2015) (Brinjikji meta-analysis 2015)

What is spondylosis?

A general word for wear of the spine with age, including discs and the small facet joints. The NHS says cervical spondylosis, in the neck, is a normal part of ageing and many people have no symptoms. (NHS neck) (Brinjikji 2015)

When should I get help for back pain?

The NHS says to call 999 or go to A&E for back pain with pain, tingling, weakness or numbness in both legs, loss of feeling around the genitals or anus, or changes in bladder or bowels. It lists other signs that need a GP or urgent help. (NHS back pain)