Types of bulging discs categorized by location and deformity

Bulging Disc

As we grow older, the shock-absorbent discs located between the vertebrae in our spine can lose elasticity, which may lead to various types of bulging discs. This form of disc degeneration is a natural occurrence in which discs become dry and brittle over time, since they don’t have a blood supply of their own to maintain robust fluid levels. Without these vital fluids, it becomes difficult for discs to regain their structure after a full day of expanding and contracting with the movements of the spine. In addition to dehydration, the daily pressures placed on discs eventually can cause them to further weaken and permanently bulge out from between the vertebrae. In most cases, a bulging disc won’t cause pain and can therefore go undiagnosed. It’s usually not until the bulging disc hits the spinal cord or a nearby nerve root that a person will experience symptoms. Even once this nerve compression occurs, it may not be immediately identified as a symptom of a bulging disc.

Types of Bulging Discs by Location

Bulging discs may be categorized by their location in the cervical (neck), thoracic (middle back) and lumbar (lower back) regions of the spine, and these different types of bulging discs can cause different reactions throughout the body. For example, a bulging disc in the cervical region that’s pressing on a nerve root may affect the shoulders, arms, hands and other areas in the upper body. Similarly, a bulging disc that compresses a nerve root in the lumbar area may cause symptoms in the buttocks, hips, legs, feet and other parts of the lower body. These symptoms may range between weakness, numbness, tingling, pain or a feeling of heat. A bulging disc that compresses the spinal cord, however, may cause myelopathy, a clinical syndrome in which the patient may experience numbness or weakness in any area below the point of compression, as opposed to having symptoms in one specific limb or area. Although a bulging disc may occur almost anywhere in the spine, approximately 90 percent occur in the lumbar region.

Types of Bulging Discs by Deformity

When we categorize the different types of bulging discs by the way the disc expands, there are three main types: symmetrical bulges, protrusions and extrusions. A symmetrical bulging disc occurs when disc expands its borders equally in every direction. A protrusion, on the other hand, is when the disc’s border expands in one direction. If this bulge involves 25 to 50 percent of the disc’s circumference, it’s considered a broad-based protrusion. There are also focal protrusions, in which less than 25 percent of the disc’s circumference bulges in one direction. If this focal bulge takes on the shape of a bubble, then the bulging disc can be classified as an extrusion.

Possible Causes and Risk Factors of Bulging Discs

Regardless of what type of bulging disc someone has, they typically want to know what caused it. Most of the time, bulging discs develop over years of every day wear and tear on the spine; however, it’s possible that the normal degeneration of intervertebral discs can be accelerated or exacerbated by several risk factors. Some of these risk factors may include:

  • Genetics
  • Obesity or inactivity
  • High-impact sports
  • Repetitive movements
  • Poor posture
  • Alcohol or tobacco use
  • Injuries or trauma

While there is no exact science to determining which of these factors may lead to disc degeneration, understanding the possible causes and risk factors will help those diagnosed with bulging discs to correct habits that may accelerate degeneration.

If you’ve been diagnosed with any of these types of bulging discs, and other treatment options have failed, contact Laser Spine Institute to learn more about our minimally invasive procedures.

Browse Related Resources