Your MRI report came back and it used a word you have never heard before. Bulge. Protrusion. Herniation. Extrusion. Nobody sat down and explained the difference, and now you are searching at eleven at night trying to figure out how worried to be. This is the explanation I give patients in our office every single day.
What is a spinal disc made of?
A disc is a cushion sitting between two vertebrae, and it has two parts. The outer wall is called the annulus, made of tough, rubbery collagen fibers with the elasticity of an earlobe. The center is the nucleus pulposus, a gel that is roughly 70 percent water. That structure is what lets you bend, twist, and absorb load.
Everyone compares a disc to a jelly-filled donut, and it is a fair comparison. The dough is the annulus. The jelly is the nucleus. Behind that donut sits the spinal canal carrying the cord, and at every level a nerve branches off each side and heads out to the body. That geometry is the whole story. When jelly moves backward, it moves toward the two structures you least want it near.
How do disc injuries actually happen?
Most disc injuries are not one dramatic moment. They are the end result of load being distributed badly over a long period, usually because some muscles are doing too much work and others have quit entirely. The disc absorbs the shearing forces that the muscles were supposed to manage, and eventually it gives.
The pattern I see constantly is lower cross syndrome. The glutes stop firing. The erector spinae muscles in the back get chronically overtight to compensate. The small multifidus muscles that stabilize each individual segment disengage. Now every time you bend or twist, forces are running through the disc at angles it was never designed to handle. The ligaments do not support it, and one ordinary movement becomes the one that finally does it.
What is the difference between a disc bulge, a herniation, and an extrusion?
They describe how far the jelly has gone. A bulge means the disc is pushing outward but the outer wall is still intact. A herniation means the jelly has broken through the fibers and is oozing out. An extrusion means a large amount has come out and migrated upward or downward away from the disc space. Bulge is the mildest, extrusion is the most severe.
Squeeze a jelly donut gently and the whole thing distorts outward without anything escaping. That is a bulge. Squeeze it harder and jelly starts to ooze through the dough. That is a herniation, and “slipped disc” is the same thing in plain language. Squeeze it hard and a slug of jelly shoots out and travels. That is an extrusion.
All three can cause leg pain, which surprises people. A bulge is not automatically harmless and an extrusion is not automatically hopeless. When a patient sits down with me for a consult and the report says extrusion, I take it seriously and I want to know the size. But it is not the end of the conversation, and we have published on exactly that.
What about degenerative disc disease?
Degenerative disc disease is not an injury event. It is the disc slowly dehydrating and losing height over years, which makes it stiffer, less shock-absorbing, and more vulnerable to a real injury. The classic symptom is morning stiffness and loss of flexibility rather than pain shooting down the leg.
Think about the tires on your car. You drive and you drive and eventually the tread wears down. It did not happen on one drive. That is what is happening to a degenerating disc, and the reason it matters is that a worn tire is the one that blows out. If you have degenerative changes, you are more prone to the bulge or herniation that comes next.
Does the size of a disc herniation matter?
Size matters, but not the way most people assume. In 14 years of practice, here is how I categorize lumbar findings: 0 to 4 millimeters is small, 5 to 9 millimeters is substantial, and 10 millimeters or more is where I want a surgical opinion in the room alongside whatever we do.
That top category does not mean we cannot help you. It means we tread carefully, we go slowly, and we make sure the right other practitioners are involved in case we need them. I have treated everything from a 1 millimeter finding to a 1.9 centimeter finding. Size changes how we approach it and how cautious we are. It does not by itself decide the outcome.
Why does the location of a disc bulge matter more than the size?
Because a large disc injury sitting where nothing important lives may cause no symptoms at all, while a small one sitting directly against a nerve root can be debilitating. Location determines what gets compressed, and what gets compressed determines what you feel.
There are two main directions a disc goes. Central means straight back toward the spinal canal. Posterolateral means back and off to the side, which is where the foramen sits, the small tunnel the nerve exits through. Posterolateral is the one that produces leg pain, numbness, and tingling running into the buttock, down the side of the leg, and into the foot.
My own case is the best example I have. I had a 5 millimeter L5-S1 posterolateral herniation at age 35. Five millimeters is substantial but it is nowhere near 1.5 centimeters. The problem was that it was abutting the exiting nerve root, which is the radiologist’s word for touching it. My hip was on fire and I had pain all the way into my pinky toe. Ten years into practice at that point, and none of what I knew touched it.
Can you have a disc bulge and no symptoms at all?
Yes, and it is far more common than most patients realize. Imaging studies of people with no back pain whatsoever find disc bulges and degenerative changes at high rates, and the rates climb steadily with age. A disc finding on an MRI is not automatically the cause of your pain.
This is one of the most important things: If you go hunting for disc bulges on imaging, you will find them, including in people who feel completely fine. Which means the finding has to be correlated with your actual symptoms before anyone starts treating it. Does the level match the nerve distribution of your pain? Does the side match? Does the exam match?
When those things do not line up, you have an incidental finding, and treating an incidental finding is how people spend a year and a lot of money chasing the wrong thing. We do not treat a disc we have not seen on MRI, and we do not treat an MRI finding that does not match the person in front of us.
Why do discs heal so slowly compared to other injuries?
Because after adolescence, spinal discs lose their direct blood supply. Almost every other tissue in your body gets oxygen and nutrients delivered by blood. The disc has to get them a different way, through a process called imbibition, and imbibition only works when the spine moves.
Movement pumps fluid and nutrients in and waste out. No movement means the disc goes stagnant and dehydrates. You want a grape, not a raisin. This is the actual reason sitting all day is hard on your back, and it is why cat-cow is worth doing every morning. Some people call it spine flossing, which is a good description of what it does.
It is also the mechanism behind why decompression works. The table creates negative pressure inside the disc, which does two things at once: it draws herniated material back toward the center and it pulls fluid and nutrients into a structure that cannot get them any other way. If you want the longer version, here is how non-surgical spinal decompression works.
What are the everyday signs that you have a disc problem?
There are three that make me think disc before a patient finishes the sentence. Pain when you bend forward to put your socks on. Pain when you cough, sneeze, or bear down. And leg symptoms that show up with prolonged sitting, or with standing and walking more than about five minutes.
All three are the same mechanism. Bending forward loads the front of the disc and pushes material backward. Coughing and bearing down spike the pressure inside your abdomen and spine, which the disc transmits straight to whatever it is already touching. And sustained positions let inflammation build around a nerve that has no room to spare.
If you have all three, you do not need to wonder. You need imaging. Waiting three months for an appointment while you cannot sleep is not a plan, and it is not something you should have to accept.
What exercises help a disc bulge?
It depends on the direction, and this is where a lot of people accidentally make themselves worse. Posterolateral findings often respond to extension-based movement, such as a cobra or a scorpion. Central findings often respond better to flexion-based movement, like bringing your knees to your chest.
The rule that overrides all of that: if an exercise increases your pain, or sends symptoms further down your leg, stop doing it. That is your body telling you the direction is wrong for your specific disc. Symptoms retreating up toward your back is a good sign. Symptoms traveling further down is a bad one, and it means stop.
This is also why generic back exercise routines off the internet are a coin flip. The right exercise for a central bulge is the wrong exercise for a posterolateral one, and no video can tell which you have.
Can a disc bulge heal on its own?
Sometimes, and the odds depend heavily on the type. The research on spontaneous regression shows the most dramatic injuries are actually the most likely to resorb, with sequestrations and extrusions regressing at high rates. Simple bulges are the least likely to resolve on their own, at a rate in the low double digits.
That finding surprises people every time, and it flips the usual assumption. The mild-sounding diagnosis is the one that tends to sit there. If you were told you have a bulge and to wait it out, understand what the odds on waiting actually are.
Even for the injuries that do resorb, there are two problems. It takes months, and it is often partial. Inflammation around the nerve does not necessarily leave when disc material does. If you cannot sleep, if you have been dealing with this longer than three months already, or if you are improving but too slowly to live with, waiting is not the neutral choice it sounds like.
Why don’t injections fix a disc problem?
Because a physical problem requires a physical solution. A steroid injection reduces inflammation around an irritated nerve, and that can genuinely help with pain. What it does not do is move the disc material that is pressing on the nerve. The mechanical cause is still exactly where it was.
This is the lesson from my own case. Ten years of clinical knowledge, and I tried the things I knew: chiropractic adjustments, red laser therapy, physical therapy. None of it worked, and it took me embarrassingly long to understand why. My bulge was physically touching the nerve. Nothing I was doing changed that physical fact. I ended up buying a decompression table out of desperation and was pain-free in five to eight weeks.
That is the whole reason this clinic exists in the form it does.
Is there imaging proof that discs can change without surgery?
Yes, and follow-up MRI is the only honest way to demonstrate it. Our first paper in the Journal of Contemporary Chiropractic documented four patients with lumbar disc herniations treated over eight weeks with non-surgical spinal decompression plus chiropractic care. Post-treatment MRIs showed reductions of 9, 27, 30, and 78 percent, confirmed by independent radiologists, with all four patients 100 percent pain-free and no surgery.
The second paper took on a much harder case: a 50-year-old man with a C5-6 disc extrusion, upward migration of disc material, segmental instability, and cervical myelopathy with cord compression. That is a presentation that normally goes straight to a surgeon. After a three-month program, his follow-up MRI showed a 52 percent reduction in the extrusion with no remaining cord compression, no adverse effects, and continued improvement documented a year later. Both papers are documented on our published research.
Two peer-reviewed papers is not a large body of literature and I would never claim otherwise. What it is, is measured imaging read by independent radiologists rather than testimonials. That is the standard I think you should hold any clinic to, including this one. We have performed 50,000+ decompression treatments in our Walnut Creek center, and the MRIs are the part I stand on.
When is back or leg pain an emergency?
Some symptoms need an emergency room the same day, not a chiropractic appointment. Numbness spreading into the groin or inner thighs, new loss of bowel or bladder control, or rapidly progressing weakness such as a foot that starts slapping the ground when you walk. Those require immediate evaluation.
Everything short of that is urgent rather than emergent, which is a real distinction but not a reason to wait six months. Nerves tolerate compression for a while and then they stop tolerating it. The longer a nerve sits compressed, the longer recovery tends to take once the pressure finally comes off.
What should you actually do next?
Get imaging if you do not have it. Have someone walk you through the images and show you the level, the size, the direction, and whether it matches your symptoms. Then find out whether the problem is mechanically reversible before anyone books an operating room.
A great many of the people who walk into this clinic have already been told surgery is their only remaining option, and a great many of them never end up needing it. That is the entire reason we built the avoid surgery side of this practice, and why we treat herniated discs at the disc itself instead of chasing the symptom down the leg. Do not be the patient who waits to see if it gets better. Take action and let’s fix the problem.
Frequently asked questions
Is a disc bulge the same thing as a slipped disc?
Can a disc bulge cause pain down the leg?
How many millimeters is a serious disc herniation?
Should I stop exercising if I have a disc bulge?
Do I need an MRI before starting spinal decompression?
Bring us your MRI
If you have a disc finding and nobody has explained what it means for you specifically, bring us the images. We will look at them with you and tell you what we see, including if we do not think we are the right fit. Contact Dudum Chiropractic to get started.
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