The Difference Between Herniated and Bulging Discs

September 6, 2017

Back pain is the second most common reason people take sick days—second only to the common cold. That statistic accounts for workers from every industry, indicating that back pain is not limited to any single job type. 70-85% of all people experience back pain severe enough that it requires treatment at least once in their lives, and back pain is the leading cause of disability worldwide.

Two of the most common causes of back pain are obesity, and improper technique when lifting heavy objects. Worldwide obesity rates have more than doubled since 1980. The spine and surrounding muscles simply cannot support the extra weight an obese person carries, and can result in a variety of spine injuries. Using your back muscles to lift a heavy object instead of your legs is improper lifting technique, and often results in a back injury. Compared to your leg muscles group (gluteus maximus, quadriceps, hamstrings, etc.) your lower back specifically, is much weaker and likely to become injured.

Some of the most common types of back injuries besides strained and pulled muscles, are herniated discs, also called slipped discs or ruptured discs. They are often confused with bulging discs, which are also very common and similar. This article will help you understand the difference between a herniated disc and a slipped disc, risk factors and treatment options for these types of injuries.

The Anatomy of Your Spine

Without a healthy spine, you wouldn’t be able to move. While the brain is in charge of signaling your body what to do, the spine is in charge of relaying those signals to the right places. Without the spine, the brain would be like an engine without a car to power.

The spine is made up of bones called vertebrae that protect the delicate spinal cord. Between those vertebrae are small, round cushions made of fibrocartilage and collagen, called vertebral discs. Each vertebral disc has a soft inner nucleus, consisting of a gel-like substance called the nucleus pulpous, and is surrounded by a tough, fibrous wall. The vertebral discs allow the spine to bend and twist, and act as a shock absorber, preventing vertebrae from compacting on one another.

What is a Herniated Disc?

Herniated discs get their name from hernias, which occur when an organ pushes through the muscle or tissue that holds it in place. These most commonly occur with the intestines and the abdominal wall. The same concept applies to a herniated disc, the gel-like fluid in the center of the disc pushes through the fibrous outer wall of the disc. This herniation of the disc can result in a large bulge that can press on nearby nerve roots, causing pain.

However, herniated discs don’t always hurt. In fact, it’s entirely possible to have a herniated disc and not know it. Herniated discs only cause pain when the herniated area pushes on a nerve root in the spine. Pain from a herniated disc can occur at the vertebral disc where the herniation has occurred and/or in other places, like the legs or arms. The location of pain depends on what the affected nerve root is connected to. In extreme cases, a herniated disc will cause your arms or legs to tingle, or even go numb due to the pressure on the affected nerve. In these cases, you should call 911 immediately.

What is a Bulging Disc?

A bulging disc occurs when the fibrous outer wall of the disc weakens and the nucleus pulpous is pushing to get out, but has not yet ruptured through. This causes the disc to bulge outward, which is where the condition gets its name. Bulging discs are less likely to cause pain than herniated discs because they generally do not protrude far enough to press on a nerve. However, a bulging disc is often progresses into full-blown herniated disc over time.

Clarifying the Difference

Talking about herniated and bulging discs often gets confusing because of how similar they are. That’s because the term “herniated disc” actually refers to a disc in one of four stages of herniation:

Degeneration (this is when it bulges initially)
Prolapse (this is when it bulges more)
Extrusion (this is when the gel actually slips out of the disc)
Sequestration (this is where the gel is no longer attached to the disc)

A disc in the degeneration or prolapse stage (what we call a bulging disc) is technically still a herniated disc, even though the herniation has not yet occurred. This accounts for basically all of the confusion surrounding herniated and bulging discs. The term “slipped disc” is used to refer to a herniated disc as well, because the nucleous pulposus has “slipped” out of place.

So, when someone talks about a bulging disc, they are referring to a disc in either the degeneration or prolapse stage. When someone talks about a herniated disc, they could be referring to a disc in any of the four stages. It’s impossible to know which exactly they mean unless you know for certain that they understand the difference between a herniated and a bulging disc.

What are the Risk Factors for a Herniated Disc?

Aging: Past age 30, spinal discs gradually lose fluid volume. This causes them to dry out and become more brittle. This process cannot be reverted.
Improper lifting mechanics: Whether you’re a weight lifter or just helping a friend move, lifting objects with a curved back puts extreme pressure on your spine. When you lift, do so from a squatted position, with your knees bent and your back straight. For more information on proper lifting form, check out our blog post on the subject.
Repetitive stress: If you do something that stresses your lower back frequently, like swinging a golf club or a baseball bat for example, your risk of herniating a disc is increased.
Obesity: Obesity puts you at high risk for many types of health problems, and vertebral disc issues are no exception. As you gain weight, you put more and more pressure on your discs, increasing the risk of rupture.
Genetics: Disc health has a genetic component to it, and if your family has a history of herniated discs, it’s more likely that you will incur them, too.
Traumatic Injuries: It’s rare, but occasionally an injury, such as a nasty fall, car accident, etc., can put so much stress on a disc at once that it herniates.

How are Herniated Discs Diagnosed?

When a patient comes in with back pain, a physician will usually take three steps to determine whether or not the patient has a herniated disc:

The physician will consider the patient’s medical history, since poor vertebral disc health can be inherited. They will also have the patient describe when the pain started and where the pain occurs.
Next, the physician will do a physical exam. They will test nerve function and muscle strength in the arms and legs. Most of the time, a physical examination tells a doctor everything he needs to know about the nature of an injury.
If necessary, the physician will order a CT or MRI scan on the patient. Bulging or herniated discs are easy to spot with such scans.

How are Herniated Discs Treated?

Depending on the severity of the herniated disc, there are three possible treatment options available:

Pain management

Pain management seeks to minimize the discomfort herniated discs cause. This is done either through medicine or injections. While these treatments are effective at reducing pain, they do nothing to stop the herniation from pressing on the spinal nerve.

Physical therapy

Physical therapy is a great treatment option for herniated discs because it can both relieve pain and reduce the likelihood of incurring future disc-related injuries. Poor posture, weak muscles, and obesity all contribute to a disc herniating, and physical therapy helps improve all of the above.

Surgery

Herniated discs can almost always be treated without surgery, but surgical treatments are also an option, if necessary. The orthopedic spine surgeon removes the herniated section of the disc, and closes the disc back up, effectively treating both the herniated disc and the pain associated with it.

Beacon Can Get You Back on Track

Whether you’re currently experiencing back pain or are just worried that your posture will give you trouble in the future, Beacon Orthopaedics and Sports Medicine offers a wide variety of treatment options that can help you. Our resident spine expert, Dr. Michael Rohmiller, is a master of minimally invasive spine surgery and can work with you to find the best treatment option. We also have an excellent team of physical therapists who can tailor a plan to address your disc problems pre or post herniated disc. Schedule a meeting with Dr. Rohmiller today to discuss your injury and treatment options.