What Is the Difference Between a Disc Bulge and a Disc Herniation? How Can a Car Accident Cause One or the Other?

Disclaimer: The following neither contains medical or legal advice but is for Informational Purposes Only. Consult a medical professional or attorney for your unique situation.

The human spine consists of 33 vertebrae which are divided into several regions: cervical, thoracic, lumbar, sacral, coccygeal. An intervertebral disc is placed between two vertebrae and it prevents contact between them. It has an oval shape so it tightly fits the shape of the vertebral body.1

Every intervertebral disc has two main areas which consist of different tissues and have a different function. The outer ring (annulus fibrosus) is located on the outer part of the disc, and it provides shape to disc and is also attached to both vertebrae. The inner part of this ring is filled with a much softer gel-like tissue (nucleus) which helps to absorb the forces acted on the spine. The nucleus mostly consists of fluid.1

As we age, our body transforms and significant changes occur. The same goes for intervertebral discs. With age, they lose fluid which reduces their ability to absorb forces that are transferred to the spine during normal daily activities like walking or lifting objects. Annulus fibrosus becomes more fragile and the nucleus shrinks.1

Disc bulge or herniation will occur if enough force is applied to the spine segment. Even healthy discs can experience such an injury if the force is strong enough. But in the case of degenerative discs, a lower force is required for injury.2

Disc Bulge

Disc bulge is very common in mid-aged and older people. It occurs when the intervertebral disc widens enough that ii passes the edge of the vertebral body. In most cases, at least one quarter of the disc is affected. Usually it is caused by a rupture in the outer part of the disc which is the only affected disc part. The symptoms  depend on the location of the bulge as well as the severity. It can be asymptomatic but there are also cases in which an individual will start feeling back pain thatworsens with time. Some patients can also have radiculopathy symptoms, like pain radiation from the back to arms or buttocks and legs, depending on the location of the disc bulge. It usually affects multiple discs in the spine. Some of the conditions which have a negative effect on spine health and which enhance the degenerative changes are increased age, increased body weight, low level of activity, back or neck muscle weakness, and/or frequent lifting of objects.2,3,4,5

Disc Herniation

Disc herniation will occur when the outer ring of a disc ruptures and the inside part goes out through the rupture site. The severity of herniation depends on the size of the annulus fibrosus rupture. The symptoms of disc herniation depend on the location of herniation as well as the size of the herniation. If the herniation occurs in the central posterior area of the intervertebral space, there is a chance that it won’t cause any symptoms. However, if the herniation is located on either side of the back side of discs, it can come in contact with the nerve root which leaves the spine through the opening between two vertebrae. Once tat contact happens, the individual will start feeling symptoms like back pain with possible pain radiation to upper or lower extremities, numbness or tingling in areas innervated by that nerve.2,3,4

Diagnosis of Disc Bulge or Herniation

In most cases, the initial radiographic study ordered after examination are X-rays of the involved segment of the spine. They can reveal possible fractures of the spine or degenerative changes, such as narrowing of the intervertebral space of spurs. But it will not show any of the pathological changes of soft tissue, such as disc bulge or herniation.  In order to do so, more sophisticated studies are required. CT scans will provide better images of bony structures of the spine and MRI is a great method which will reveal even the smallest disc bulge or herniation.6

An examiner will have to anticipate such an injury based on the examination, in order to indicate an MRI is needed. The symptoms which will raise suspicion on disc herniation are back or neck pain with radiation, numbness, and/or tingling of some part of the arm or leg.

Treatment Options

Treatment options will depend on the severity of symptoms and disc bulging or herniation. In the case of disc bulge, most patients will experience relief with the use of non-surgical treatment options. The most commonly used are physical therapy, NSAIDs, epidural injections, chiropractic treatments, acupuncture and many others.5

If the individual has a symptomatic disc herniation, non-surgical treatment options probably will not result in permanent or long-lasting relief. In that case, surgery might be the best and only option in order to get relief from symptoms. In most cases, the herniated part of the disc is removed so that there is no pressure on the nerve root. This will result in alleviation of symptoms. If the spine is severely and degeneratively changed, then there is a chance that another type of surgery will be required. That surgery is called spinal fusion, and it involves the fusion of vertebrae so that there is no significant movement between them, which can be the cause of severe pain or discomfort.5

Automobile Accidents and Disc Bulge/Herniation

In the case of automobile accidents, several factors will have an impact on the severity of spine injury. Most important are the amount of energy transferred to specific spine segments, the severity of degenerative changes of the spine, state of intervertebral discs, etc.

Disc bulges can be considered traumatically induced if they are directional rather than the cause of the progression of time.

If an individual has severe degenerative changes prior to an accident, then a much smaller amount of energy is required to cause a spine injury. Whiplash injury can cause severe symptoms, and if the force is strong enough it can even cause disc bulge or herniation. Increased force applied to intervertebral disc spurring hyperflexion or hyperextension can cause rupture of annulus fibrosus through which the nucleus will come out and create pressure on the nerve root. The same mechanism can occur in any other mobile segment of the spine.


  1. “Spine Anatomy, Anatomy Of The Human Spine.” Mayfieldclinic.com. N. p., 2019. Web. 20 Oct. 2019.
  2. “Bulging Disc Vs. Herniated Disc: What’S The Difference? – Penn Medicine.” Pennmedicine.org. N. p., 2019. Web. 20 Oct. 2019.
  3. “The Radiology Assistant : Spine – Lumbar Disc Nomenclature 2.0.” Radiologyassistant.nl. N. p., 2017. Web. 20 Oct. 2019.
  4. “Bulging Disk Vs. Herniated Disk: What’s The Difference?.” Mayo Clinic. N. p., 2019. Web. 20 Oct. 2019.
  5. “Herniated Disc Vs. Bulging Disc | Orthopedic & Laser Spine.” Orthopedic & Laser Spine Surgery. N. p., 2018. Web. 20 Oct. 2019.
  6. ” What Is The Difference Between A Disc Bulge And A Herniation? .” Spine.org. N. p., 2019. Web. 20 Oct. 2019.