Do you need an MRI for back pain? What pain-free scans show

Most people with low back pain don't need an MRI. Guidelines in the UK and Australia advise against routine scans, because scans of people with no back pain at all often show the same disc changes and bulges, and for most back pain no single cause can be found. A scan is mainly used when a doctor needs to rule out a serious cause, for example when warning signs are present. If your doctor asks for one, have it.

Lorimer Moseley is a clinical scientist who works on pain. In a TEDxAdelaide talk in 2011, viewed more than 1.6 million times, Moseley described people walking into hospital departments with a model spine on the desk and a disc that has slipped far out of it. "If you've ever seen a disc in a cadaver, you can't slip the suckers," Moseley told the audience. "They're immobile, you can't slip a disc. But that's our language, and it messes with your brain" (TEDxAdelaide, 10:44 to 10:52).

Moseley co-wrote the Explain Pain books on how pain works and receives royalties from them. That matters when you weigh the views, so each one below sits next to the research. By the end you'll know what pain-free scans show, when guidelines say a scan helps, and what to ask if a report lands in your inbox.

What do scans of people without back pain show?

1. Disc changes are common at every age, with or without pain

In 2015, researchers pooled 33 imaging studies of 3,110 people who had no back pain, almost all of them MRI studies, and estimated how common each finding was by age (Brinjikji et al., 2015):

A darker disc on MRI, the "black disc" (disc signal loss), showed up in more than half of pain-free people over 40. The authors concluded that many of these features "are likely part of normal aging and unassociated with pain," and that they "must be interpreted in the context of the patient's clinical condition."

Here's what that looks like in practice. A 45-year-old with a sore back has a scan that reports two disc bulges and some degeneration. Many people of that age with no pain would get a similar report. The finding may or may not have anything to do with this week's pain, and the scan alone can't say which.

2. Under 50, some findings are a little more common in people with pain

The picture isn't the same at every age. The 2018 Lancet paper on what low back pain is notes that, at least in people under 50, some MRI findings, a disc bulge among them, are a little more common in people with low back pain than in those without (Hartvigsen et al., 2018). The same paper adds that there isn't enough evidence to know whether MRI findings predict who will get back pain or how it will go. So a finding under 50 is worth taking seriously, and it's still read alongside how you are, not on its own.

3. For most back pain, no single cause can be pinned down

For the great majority of people with low back pain, the Lancet authors write, "it is not possible to accurately identify the specific nociceptive source" of the pain (Hartvigsen et al., 2018). The World Health Organization puts it at about 90% of cases: no disease or damage can confidently account for the pain, so it's called non-specific (WHO, 2023). That doesn't mean nothing is happening, or that the pain isn't real. It means a picture of the spine usually can't point to the part to blame.

"You can't slip a disc. But that's our language, and it messes with your brain." Lorimer Moseley

Why don't doctors scan most back pain?

4. Guidelines advise against routine scans

The UK's National Institute for Health and Care Excellence (NICE) tells clinicians: "Do not routinely offer imaging in a non-specialist setting for people with low back pain with or without sciatica." In specialist settings, it advises considering imaging "only if the result is likely to change management" (NICE NG59, 1.1.4 and 1.1.6). Australia's national care standard says the same to patients: an X-ray, CT or MRI "is not necessary" in most cases, and these tests "are usually only needed when your clinician needs to rule out a serious cause for your back pain" (ACSQHC, 2022).

The Lancet authors add that "there is no evidence that imaging improves patient outcomes" for people with low back pain (Hartvigsen et al., 2018).

5. A scan can add worry without adding answers

The Australian standard is frank about why. Unless there is a good reason, it says, scans "are unlikely to find the reason for your pain or change how it is treated." They "can often show changes that are normal for your age," and "knowing about these changes may worry you and can lead to further tests, consultations or treatments that do not help your back pain" (ACSQHC, 2022).

Words stick. In a survey of 130 adults with persistent or recurring back pain, most described their back as something broken, like a machine, and many saw it as permanent; 116 of them (89%) said they had learned their understanding from health professionals (Setchell et al., 2017). If you were told your spine is "worn" or a disc "went," you heard it from people you trusted, and it's fine to ask what those words mean for you.

6. When a doctor does check further

Scans have a clear job: to look for a serious cause when the picture calls for it. Serious causes of back pain are rare. More than 95% of low back pain cases don't have a serious underlying cause (ACSQHC, 2022). If any of the signs below applies, get checked.

Get medical help straight away if:

• your bladder or bowels have changed: trouble peeing, or leaking pee or poo without meaning to;
• you've lost feeling around your genitals or bottom, or sex feels different;
• both legs feel weak, numb or tingly, or you can't walk because of the pain;
• the pain started after a serious fall, accident or blow to your back;
• you have chest pain or trouble breathing with it, or the pain came on suddenly and is far worse than anything you've had before, or it's getting worse fast.

See a doctor first if:

• you have a fever, or feel hot, shivery or generally unwell;
• you've had cancer, or you've lost weight without trying;
• the pain is worse at night or doesn't change at all when you move or rest, it's high up between your shoulder blades, or one leg feels weak or numb.

If a new flare isn't getting better after a few weeks, keeps getting worse, or worries you, see a doctor. The doctor decides whether a scan is needed. If they ask for one, have it: it means something in your history or examination is worth a closer look.

How to read the words on a scan report

7. "A disc slipped out"

You may hear that a disc slipped out of place and needs pushing back. It's a popular message. In a Spanish-dubbed video by fitness coach Jeff Cavaliere, whose ATHLEAN-X channel sells training programs, with more than 5 million views, the disc is pictured as something to be re-centered in a few steps and fixed for good (ATHLEAN-X Español). The research doesn't support that picture. Discs are held in place, as Moseley says, and disc bulges are common in people with no pain at all (step 1). The same video, to its credit, notes that MRIs show disc problems in many people who have no symptoms.

Spanish physiotherapist Marcos Sacristán takes on the related myth that back pain comes from "a vertebra out of place," a myth Sacristán traces to badly explained hands-on therapy. "El dolor no depende de una vértebra fuera de su sitio" ("The pain doesn't depend on a vertebra out of place"), Sacristán says, and "tu columna es una estructura tremendamente estable" ("your spine is a tremendously stable structure") (Fisioterapia a tu alcance, 6:02 and 6:26). Nothing in your back needs putting back.

8. "The disc is dark and dried out"

You may hear that a dark disc on MRI is diseased and needs rehydrating. In a Brazilian video with nearly 3 million views, physiotherapist Kelwin Juan, who sells a home exercise program, shows a darker disc on a scan and recommends a daily glass of salted water to rehydrate it (Kelwin Juan, in Portuguese). Nothing in our sources shows a drink changes a disc. And the dark disc itself, disc signal loss, was found in more than half of pain-free people over 40 in the 2015 review (Brinjikji et al., 2015). The video does get one thing right near its end: more movement tends to go with less pain.

9. "Degeneration," "bulge," "wear and tear"

These are descriptions of what the scan shows, and the same words turn up on reports of people with no pain. "Degenerative disc disease" sounds like a diagnosis, but in the pain-free review, disc degeneration was more common than not from age 40 onward. Treat the words as a picture of a spine at your age, and ask your doctor what they mean for you.

On that last question, guidance is consistent: "Do not wait for all the pain to be gone before you start moving" (ACSQHC, 2022). NHS inform's advice for back problems is plain too: "For most back pain problems, you'll not normally need an X-ray or MRI scan," and "most problems should have improved within 6 weeks" (NHS inform). Our guides to what to do in a flare and lower back pain cover the days in between, and lifting with back pain covers bending.

Back to the plastic spine

Moseley's model spine, with its disc slipped far out, is a picture many people carry home from an appointment. The research gives a different one: disc changes are common with or without pain, a disc can't slip, and for most back pain a scan can't find a single part to blame. A scan still has its job, when a doctor needs to rule out a serious cause. In Moseley's words, the slipped disc is "our language." You can choose different words for your own back.

To work out what helps your back day to day, try the 1h Protocol to Manage Back Pain, a program of practical education. Its free first chapter starts with a quick check for warning signs, then asks how your back days go and finds your pattern, one of four or the Tune-up, with one thing to do tomorrow. The full program takes about an hour: seven chapters show why your back keeps flaring, clear up the myths (scans included), walk one back day with you at your own times, and plan a flare and the days after it. You leave with two or three things to start now, each with an alternative for harder days, a flare plan with one line in your own words, a flare card for your lock screen, and fourteen days to try it, with a sheet, reviews on days 7, 14 and 30, and four one-tap check-ins by email if you're signed in. Start free

Frequently asked questions

Do I need an MRI for back pain?

Usually not. UK and Australian guidance advise against routine scans for low back pain, and say they're mainly needed when a doctor has to rule out a serious cause (NICE NG59; ACSQHC, 2022). Your doctor decides; if they ask for a scan, have it.

Are disc bulges normal?

They're common in people with no back pain: in a review of 33 studies, disc bulges were found in 30% of pain-free 20-year-olds and 84% of pain-free 80-year-olds (Brinjikji et al., 2015). Under 50, a bulge is a little more common in people with back pain, so it's read alongside how you are (Hartvigsen et al., 2018).

Can a disc slip out of place?

No. Discs are held in place between the vertebrae, and "you can't slip a disc," as Lorimer Moseley puts it (TEDxAdelaide, 10:49). "Slipped disc" is everyday language for findings such as a bulge or protrusion, which scans also show in many people without pain.

Why don't doctors scan most back pain?

For most low back pain, no single cause can be identified, scans often show changes that are normal for your age, and there is no evidence that imaging improves outcomes (Hartvigsen et al., 2018). The Australian standard adds that knowing about these changes may worry you and lead to tests and treatments that don't help.

What if my scan shows something?

Ask your doctor what the finding means for you, whether it's common at your age without pain, and what to do next. Many findings, such as disc degeneration and bulges, are common in pain-free people. Follow your doctor's advice, and see a doctor promptly if any warning sign appears.

Sources

This article draws on Lorimer Moseley's TEDxAdelaide talk, videos by Marcos Sacristán, Jeff Cavaliere and Kelwin Juan, and the studies and guidance listed below.

• Lorimer Moseley, Why things hurt (TEDx talk, TEDxAdelaide, 2011)
• Marcos Sacristán, 5 mitos del dolor de espalda (YouTube video, Fisioterapia a tu alcance, in Spanish, 2026)
• ATHLEAN-X Español, Jeff Cavaliere, Cómo arreglar una hernia discal sin cirugía (YouTube video, in Spanish, 2018; cited as a myth source)
• Kelwin Juan, Um copo por dia e diga adeus à hérnia de disco (YouTube video, in Portuguese, 2025; cited as a myth source)
• Brinjikji et al, Systematic literature review of imaging features of spinal degeneration in asymptomatic populations (systematic review, 33 studies, 3,110 people without back pain, 2015)
• Hartvigsen et al, What low back pain is and why we need to pay attention (narrative review, The Lancet Low Back Pain Series, 2018)
• Setchell et al, Individuals' explanations for their persistent or recurrent low back pain (cross-sectional survey, 130 adults, 2017)
• NICE, Low back pain and sciatica in over 16s (NG59), recommendations (clinical guideline, 2016, updated 2026)
• Australian Commission on Safety and Quality in Health Care, Low Back Pain Clinical Care Standard, information for consumers (national care standard, 2022)
• World Health Organization, Low back pain (fact sheet, 2023)
• NHS inform, Back problems (health information page, 2026)