So your doctor has told you that you have a disc bulge.
Maybe you’ve had a scan, maybe you’ve read the report, and now you’re sitting there wondering what that actually means for your back. Is it serious? Is it going to get worse? Should you stop moving?
Those are really common questions — and honestly, the word “bulge” doesn’t help. It sounds like something’s about to burst.
My name is Fardis. I’m a physiotherapist at The MSK Studio in Adelaide, and most of my day is spent working with people who have back and neck pain. In this post I want to walk you through what’s actually going on.
We’re going to cover what a disc is, what a disc bulge means, why your scan isn’t the whole story, what tends to help during a flare-up, the signs that mean you need to see a doctor, and the other things that may be driving your pain.
By the end, you should have a much clearer picture of what’s going on in your back. Understanding it is the first step to doing something about it.
Dealing with a disc bulge or lower back pain in Adelaide? Our low back pain physiotherapy service and disc herniation condition page cover what to expect from assessment and management. Book an initial session.
What Is a Disc?
Let’s start with the basics.
The lumbar spine — your lower back — is made up of vertebrae (the bones), the spinal canal (where your nerves travel), and the discs sitting between each vertebra.
Discs have two important jobs.
The first is shock absorption. Every time you walk, run, jump or land on something, the discs take some of that load and spread it through the spine. That way no single part of your body is absorbing all the force.
The second is movement. Think of a disc a bit like a water balloon sitting between two bones. It has a tougher outer layer — the annulus fibrosus — and a softer, gel-like centre — the nucleus pulposus. When you bend forwards, that softer centre shifts towards the back. When you bend to the side, it shifts the other way. That shifting is what allows the spine to move smoothly without the bones grinding against each other.
So when your doctor says “disc bulge”, this is the structure they’re talking about. Knowing what the disc is and what it does makes everything that follows a lot easier to understand.
What Is a Disc Bulge?
A disc bulge is when the disc extends a bit past its normal boundary — usually towards the back or one side. You’ll also see the term “disc herniation.” They’re related but not quite the same thing.
A bulge tends to be broader and more spread out around the disc. A herniation is usually a more localised spot where the inner material has pushed further out through a tear in the outer layer. Our disc herniation conditions page covers the full picture for those presentations specifically.
There usually isn’t one single cause of a disc bulge. Things that may contribute include:
- Stiffness in the joints around that level of the spine
- A sudden increase in load, such as a big weekend of lifting or gardening
- Movement patterns that put repeated stress through one area, often because other areas are stiff or not moving well
- Normal age-related changes in the disc over time — including gradual degenerative disc disease
When a disc gets irritated, it can cause inflammation in the surrounding area. And because the disc sits right next to the nerve roots, it can sometimes irritate or press on a nerve root as well. That’s when you might feel symptoms travelling away from your back — pain into the glute or down the leg, pins and needles, or numbness. That pattern is what people often call sciatica.
One thing worth knowing: discs have very limited blood supply of their own. Most of their nutrition comes from fluid moving in and out as you load and unload the spine through movement. That’s one of the reasons gentle, regular movement tends to help — every time you move, you’re helping get nutrients into the disc.
Research suggests that disc herniations can reduce in size over time on their own — a process the body initiates without intervention. That doesn’t happen for everyone, and the timeline varies, but it’s a more hopeful picture than most people expect after reading a scan report.¹
Why Your Scan Isn’t the Whole Story
If you’ve just been told you have a disc bulge, it’s completely natural to assume that’s the cause of your pain. It’s right there on the report.
But it isn’t always that straightforward.
In 2015, researchers led by Brinjikji reviewed 33 studies looking at the spinal scans of people who had no back pain at all.² A significant proportion of those people had disc bulges on their scans:
In people in their 20s — around 30% had a disc bulge
By their 40s — approximately 50%
By their 60s — closer to 69%
These were people with no pain. The disc changes were there. The pain wasn’t.
What does that tell us? It tells us that a disc bulge may have been sitting there quietly for years before your pain ever started. The scan shows what’s there. What it can’t always tell us is why it’s hurting now — or whether it’s the primary driver of your symptoms at all.
I think of disc bulges a bit like grey hair or wrinkles on the inside. They’re a really common part of how our bodies change over time. On their own they don’t automatically mean something is wrong.
That doesn’t mean the disc bulge is irrelevant. For some people it’s a significant part of the picture. But it’s one piece of the puzzle — not the whole thing. If we treat it like the whole thing, we can end up chasing the wrong answer. This is the same principle behind why the clinical picture matters more than what a scan shows in disc-related conditions more broadly.
If You’re in a Flare-Up Right Now
If you’re in the middle of a flare-up, there are two things worth hearing.
The first: how much it hurts isn’t always a measure of how much damage there is.
The disc sits very close to a network of nerves. When that area gets irritated, those nerves can produce significant pain — even from a fairly minor irritation. So severe pain is real and it’s awful, but it doesn’t automatically mean something is badly damaged.
The second: rest isn’t always the answer.
It makes sense to want to lie down and wait it out. And a bit of relative rest in the first day or two can be reasonable. But long periods of complete rest can make things harder. The muscles around the spine tend to tighten up, the joints stiffen, and there’s less movement helping get fluid and nutrients into the disc.
What tends to help more is staying gently active within what you can tolerate. Short walks. Changing positions regularly. Movements that feel okay, even if they’re small.
If you’re not sure where to start, our post on 5 physiotherapy exercises for lower back pain flare-ups covers a gentle sequence you can work through at home.
In a physiotherapy context, the early focus is usually on settling things down and getting movement restored. That often means hands-on treatment to help ease the irritation alongside simple mobility exercises to keep progress going between sessions. The two tend to work best together.
Red Flags — When To See a Doctor Immediately
For most people, a disc bulge can be managed without surgery or emergency care. But there are specific signs that mean you need medical help promptly.
Please see your doctor or go to the emergency department if you notice any of the following:
- Numbness or pins and needles in the groin, inner thighs or around the area you’d sit on a saddle
- Any new changes to your bladder or bowel — trouble passing urine, inability to hold it, or loss of bowel control
- Weakness in your leg or foot that’s getting worse, such as your foot slapping down when you walk
- Symptoms travelling down both legs at the same time
- Back pain accompanied by fever, unexplained weight loss, or a history of cancer
These signs are rare, but they matter. They can indicate that a nerve is under significant pressure and require urgent attention. If you’re ever unsure, get it checked.
The Other Things That May Be Driving Your Pain
If the disc bulge is only one piece of the puzzle, what are the other pieces?
Low back pain is rarely caused by just one thing. Here are some of the factors assessed alongside the disc when someone comes in:
How you move. If parts of your spine or hips are stiff, other parts often end up doing extra work. Over time, that can place more repeated load through one area. A stiff mid or upper back, for example, may mean the lower back takes on more load over time — which is worth exploring through spinal physiotherapy assessment.
Whether your body can handle what you ask of it. Your muscles need enough strength and endurance to support your work, training, and daily demands. When those demands increase faster than your capacity, things can get irritated. This is the load and capacity principle — covered in detail in our post on why lower back pain keeps flaring up.
Stress. Ongoing stress can make the nervous system more sensitive, which can amplify pain signals.
Sleep. Poor sleep can make pain feel worse and slow recovery.
Activity levels. Both doing too little and suddenly doing too much can play a role.
All of these matter. And if we only focus on the disc bulge and ignore everything else, we may miss what’s actually most relevant for your presentation.
The good news is that many of these factors are things you can work on. Addressing them is often a significant part of managing things long term. This is where clinical pilates and progressive rehabilitation at The MSK Studio comes in — building capacity in a graduated way so that your spine can handle the demands being placed on it. For people dealing with recurring disc-related back pain, The Resilient Spine Method is a structured 12-week program built around exactly this approach.
To Bring It All Together
A disc is the cushion between the bones in your spine. It absorbs shock and allows movement. A disc bulge is when that disc extends past its usual boundary, and it may irritate the surrounding area or the nearby nerve roots. But plenty of people have disc bulges with no pain at all — which means the scan is only one part of the story.
If you’re in a flare-up, the pain can feel alarming, but it doesn’t always indicate serious damage. Gentle movement tends to help more than extended rest. Know the red flags. And look at the whole picture — how you move, your strength, stress, sleep, and activity.
Understand it first. Then you can start to work on it.
If you’re based in Adelaide and want to understand what’s actually contributing to your lower back pain, you can book an initial low back pain physiotherapy session at The MSK Studio. The session covers a full history, a physical assessment, and a plan built around what’s found — individual presentations vary, and the aim is to give you a clear starting point for your specific situation.
We see patients at our Adelaide location:
Clovelly Park (South Adelaide) — 1140 South Road, Clovelly Park SA 5042
References:
Chiu, C.-C., Chuang, T.-Y., Chang, K.-H., Wu, C.-H., Lin, P.-W., & Hsu, W.-Y. (2015). The probability of spontaneous regression of lumbar herniated disc: A systematic review. Clinical Rehabilitation, 29(2), 184–195. https://doi.org/10.1177/0269215514540919
Brinjikji, W., Luetmer, P. H., Comstock, B., Bresnahan, B. W., Chen, L. E., Deyo, R. A., Halabi, S., Turner, J. A., Avins, A. L., James, K., Wald, J. T., Kallmes, D. F., & Jarvik, J. G. (2015). Systematic literature review of imaging features of spinal degeneration in asymptomatic populations. American Journal of Neuroradiology, 36(4), 811–816. https://doi.org/10.3174/ajnr.A4173
