Bulging and Slipped Disc Symptoms

Illustration of a spinal disc herniation between L4/L5 (4th and 5th lumbar vertebrae) and L5/S1 (5th lumbar and 1st sacrum)
BSIP/UIG/Universal Images Group/Getty Images

Bulging and slipped discs, while not exactly the same thing, are in the same family of spinal problems. These injuries relate to the structural integrity of your spinal discs; the terms refer to the outward migration of the soft, jelly-like substance that is normally located in the center of the disc. 

In some cases, the nucleus, as this substance is called, escapes the confines of the disc structure altogether, in other cases it doesn't. 

The difference in terms is mainly a matter of degree. Sometimes a disc "blows out" all at once, which is called a disc herniation. But that's not always how it happens. 

Age related spinal degeneration, a minor injury to the outside of the disc and/or other types of degeneration may result in internal only movement of the nucleus, without disruption to the container that surrounds it. This is a bulging disc.

Doctors and other spine experts use terms to describe the stage of movement or disc migration. The three main types are:

  • Prolapse, which is essentially a bulging disc, as described above. In this type, the nucleus can be viewed on an MRI as bulging out between the spinal bones directly above and below. But the outer most layers of the disc, which is made of several rings of tough fibers strong enough to hold the nucleus in remain intact.
  • Extrusion, where, due to a tear in the tough outer fibers, some of the nucleus is able to escape, but the nucleus remains connected to the central part of the disc.
  • Sequestration, otherwise known as a herniated disc or, in layman's terms, a slipped disc, occurs when some or all of the nucleus not only escapes, but is disconnected from the disc as well.

Bulging and slipped discs, as well as extruded discs, can occur in any of the three main regions of the spine. In other words, these injuries happen in the neck, upper or mid-back and in the low back. They don't affect the sacral or coccyx regions as there are no intervertebral discs there, and occur only rarely in the thoracic spine.

Symptoms of Slipped Disc

By the way, the fact that you have one of these injuries does not automatically mean you'll have symptoms. But often you will. In the case of slipped or herniated disc, symptoms usually come about when the dislodged disc tissue makes contact with a spinal nerve root.

Symptoms associated with slipped disc are generally due to compression of the herniated material as it contacts a spinal nerve root; these symptoms are called radiculopathy. Many people, especially non-medical people, refer to these symptoms as sciatica.

But sciatica is actually a more general term than radiculopathy. It does not describe how, exactly, the disc makes for pain and other issues. Radiculopathy symptoms include pain, numbness, weakness, and/or electrical sensations such as pins and needles, burning or shock, that go down just one leg or one arm (depending on the location of the injury.) Sciatica is used to refer to leg pain with any number of causes, and therefore, a variety of affectations.

Most disc herniations occur in a "posteriolateral" direction, which is a combination of back and side; the movement you do when you sustain this type of injury will likely be the determining factor as to which side experiences the herniation, and therefore which limb gets the radiculopathy symptoms.

A herniated disc in the low back sometimes leads to numbness in the seat area (perineum) or saddle anesthesia, loos of bowel or bladder control, or it may cause your legs to get progressively weaker. These are symptoms of a very serious condition known as cauda equina syndrome. Cauda equina can be a medical emergency. If you experience these, you should seek medical attention.

What's the Difference between Herniated and Bulging Disc Symptoms?

Symptoms of a bulging disc are similar to herniated disc symptoms, in other words, back pain and/or symptoms that go down your leg or arm. Again, extremity symptoms may include pain, weakness, numbness and/or electrical sensations such as tingling and the others mentioned above. Certain causes of neck radiculopathy may lead to dizziness, but this is rare.

The difference between them lies more in how often they show up and how severe they are, that what you'll likely notice. 

While both conditions cause symptoms when disc material compresses a spinal nerve root, disc material that has completely separated from the main structure, as is the case with herniation, tends to move around more freely and can generally more easily migrate to where the nerve root or cord is located.

Which means chances are your herniated disc will be much more uncomfortable than your bulging disc. 

Was this page helpful?
View Article Sources