Those who've experienced a herniated disc describe it as crippling pain shooting into the legs. But in some cases, there might be no pain at all. Let's talk about all you need to know about herniated discs.
What Are Spinal Discs? A Sort of Shock Absorber for the Spine
The spine mainly consists of 33 or 34 bones called vertebrae. However, the body also needs a way to dampen the shocks caused by movement. This is partly achieved through the spine's curvature, and partly through the spinal discs.
Spinal discs are elastic pads sandwiched between the vertebrae. They have high water content, making them squishy and good at dampening shocks.
Interestingly enough, the discs are not supplied with blood by any veins. Instead, they are nourished by cerebrospinal fluid, which is mechanically pumped through them by the compression that naturally occurs when moving. Put simply, natural and healthy physical activity is essential for proper nourishment and dampening function of spinal discs.
People who don't get enough exercise (for example, because they sit all day) can develop problems. Without movement, the discs do not compress, the cerebrospinal fluid doesn't circulate, and disc tissues necrotise (their cells die off).
We'll get back to the importance of activity later in the article.
How Many Discs Are There? Fewer than You Might Expect
The human spine has 23 discs. This is obviously less than the number of vertebrae, which are 33 or 34. This is because the 1st and 2nd cervical vertebrae have no disc between them, and neither do any vertebrae below the 1st coccygeal.
The top two vertebrae are rather specific. They are linked in such a way as to allow maximum mobility for the head, which precludes the presence of a disc. Meanwhile, the vertebrae of the coccygeal segment in humans are fused into a solid bone mass called the coccyx, and no longer have any discs between them.
What Do Spinal Discs Look Like? Kind of Like a Cup of Jelly
To understand the mechanism of disc herniation, we first need to look at the anatomy of spinal discs. The core of a disc (the nucleus pulposus)is a gelatinous substance with high water content, surrounded by a ring of cartilage (the annulus fibrosus).
The core fluid serves as essentially a ball bearing on which the vertebrae tilt when you move. The cartilage ring compresses on one side and stretches on the other; its exterior is lined with reinforcing fibrous lamellae to withstand this.
What Exactly is Disc Herniation?
A spinal disc is a pulpy core inside a tough cartilage jacket. If it's subjected to one-sided pressure for a long time, it will start to deform, and the gelatinous core will migrate to one side. This is called protrusion, and is among the most common spinal disc injuries. Poor posture leads to one-sided load on the discs, which eventually deforms them into a wedge shape. The soft core moves towards the disc boundary on the thin side and the fibrous wall bulges outward, possibly pinching nearby nerves.
If overloading continues, the fibrous wall eventually ruptures completely and the core material spills out.
Why Is Disc Herniation a Problem?
Aside from the loss of much of the disc’s shock-absorbing function, the principal issue is that the bulge of the fibrous wall or later the escape of the core fluid impinge on nearby nerves. This may cause any or all of the following symptoms:
back pain, which can be severe enough to mostly prevent physical activity
shooting pain in the legs
numbness or pins-and-needles sensation in the legs
leg paralysis, if the herniation reaches the spinal cord
The function of the urethral sphincter can also be impaired, causing incontinence.
Most of the listed symptoms affect the lower part of the body, which will be the case if the herniation occurs in the lumbar area, the most frequent location. If the herniation instead occurs in the thoracic or cervical spine, the symptoms will affect the arms instead, including numbness, pins-and-needles sensations, and impaired motor control.
A herniated disc is not always painful. When should you visit a doctor?
Not all disc herniations present with the symptoms listed above. It will depend on the volume of fluid that escaped the disc and what nerves (if any) it struck.
You should definitely see a doctor when:
You feel severe back pain (this may have other causes, but those generally merit professional help as well)
The pain progresses to the arms or legs
You have a pins-and-needles sensation or numbness
Your arms or legs feel weak
You experience sudden-onset incontinence
You will be examined by a neurologist, who will determine the appropriate treatment. Severe cases of disc herniation usually require surgery, but most patients can be treated with medication and exercise.
A Herniated Disc Is Not Forever. Treatments Include Medication, Exercise, and Surgery
The treatment option you’ll have most likely heard about for herniated discs is surgery. In recent years, however, doctors have been recommending surgery less often, generally only in severe cases.
This occurs in a rather high percentage of cases, and essentially means the surgery must be redone multiple times. I’ve seen patients who’ve had three back surgeries for the same thing. Not to mention, herniated disc surgery is not exactly a trivial procedure.
The pain may return after surgery for several reasons:
The surgery leaves an internal scar, which impinges on a nerve
The part of the spine near the surgery site needs to be stabilized for some time, overloading other parts
Post-surgery tissue inflammation
For these reasons, the modern approach to herniated disc treatment is to rely on medication and exercise whenever possible.
How to Prevent Disc Herniation? With Activity, Walking, and Proper Seated Posture
No treatment can guarantee either the same or a different disc won’t herniate again, making prevention important for everyone.
Let’s start our talk of prevention by listing the most common causes of herniated discs:
Aside from the last item, these are mostly different forms of overloading or asymmetrical loadingof the spine. Such problems are not limited to those with physically difficult jobs; they may occur in the office as well. Office workers tend to spend most of their days sitting and putting their spine in various poor postures.
Much of this can be prevented by healthy, active sitting. Normal office chairs (including “ergonomic” ones) only allow passive sitting, which leads to hunching and overloading of the lumbar and cervical spine. The spine is “designed” to move, and a severe enough lack of motion can damage it.
Switch to a “therapeutic” chair, meaning a chair with a tilting seat. This allows your spine to constantly move around slightly, avoiding overloading. Weight is better distributed among spinal discs and the motion variously compresses and decompresses them, which they need to remain nourished.
Therapeutic chairs allow a forward tilt of the pelvis, which helps prevent disc herniation. You could achieve the same effect on a gym ball, but this lacks a relaxed position, as there is no back- or armrests. A relaxed position is necessary to reduce static loads on the spine and spinal disc compression.
How do you recognize a suitable therapeutic chair?
Best Exercise for Preventing Disc Herniation? Walking
Aside from healthy sitting, simple walking helps as well. Walking is largely what the human body is built for. The spine remains straight and none of its parts are overloaded, regular compression feeds nutrients to spinal discs, and most of the body’s muscles get natural exercise.
If you spend most of your day sitting, include some walking in your daily plan. Walk to and from work if you can, or just go for a stroll.
Most Common Questions About Herniated Discs
How can I tell I have a herniated disc?
The typical symptoms of a herniated disc include:
shooting pain in arms or legs
pins-and-needles sensation or numbness in limbs
There are, however, cases where herniation is painless, when it misses the nerves.
Does a herniated disc require surgery?
Not necessarily. Your physician will recommend appropriate treatment, but in most cases, this will consist of medication and exercise. Surgery may be required for acute cases.
Which exercises are suitable for post-surgery rehabilitation?
Your physician will recommend suitable exercises. It will depend on which disc was affected and your overall physical condition.
Do herniated discs happen in the cervical or lumbar area?
Yes, they do. Cervical and lumbar disc herniations are the most common.
Do herniated discs happen in the thoracic area?
Yes, but it is less common than herniations in the cervical and lumbar segments.
Can herniated discs be psychosomatic in origin?
It's highly unlikely. Disc herniation can have any number of causes, but generally it requires a mechanical component – physical overloading, poor posture, one-sided strain, etc.
What does a herniated disc feel like?
Patients usually describe severe back pain that shoots out into the limbs. There can also be a pins-and-needles sensation or numbness.
How is disc herniation treated?
You will first be examined by a neurologist, who will select an appropriate course of treatment. Acute cases typically require surgery, but the more common chronic cases are usually treated with medication and exercise.
How can I prevent disc herniation?
Exercise often and avoid one-sided overloading and static sitting. If your work is sedentary, consider a therapeutic chair with a tilting seat.
I am a physical therapist with over 10 years of experience, specializing in spine and spinal cord injuries. I am also a Nordic walking instructor accredited by the Czech Ministry of Education, and personal physical therapist to the current Czech champion and Czech indoor record holder in disability shot put.