What Is A Bulging Disc Versus A Herniated Disc?

The spinal column is comprised of 24 individual vertebrae that make up the cervical, thoracic, and lumbar spine, in addition to nine fused vertebrae that make up the coccyx and sacrum. Between each of the individual vertebrae is an intervertebral disc. The intervertebral discs provide shock absorption as well as stability for the spinal column. Each intervertebral disc consists of a nucleus pulposus (inner layer) and an annulus fibrosis (outer layer).

When talking about intervertebral discs, the terms bulging disc and herniated disc are often used interchangeably; however, they are two distinct conditions. Disorders of the intervertebral disc can be classified as contained or non-contained. A herniated disc falls into the category of a non-contained disc disorder, whereas a bulging disc would be an example of a disc disorder that is contained.

A bulging disc means that there is no tear or rupture in the annulus fibrosis (outer layer) of the intervertebral disc. A bulging disc is also known as a disc protrusion. Essentially, a small bubble of disc material protrudes into the spinal canal. Most importantly, no part of the nucleus pulposus has leaked out of the intervertebral disc. Many individuals have bulging discs and are unaware of the condition until it is found incidentally on routine imaging.

Conversely, a herniated disc means that a tear or rupture in the annulus fibrosis is present, and that a portion of the nucleus pulposus has leaked into the spinal canal, but is still connected to the intervertebral disc. This is known as a disc extrusion. However, if a portion of the disc breaks off and drifts into the spinal canal, it is referred to as a sequestration. A herniated disc may have begun as a bulging disc, but when there was enough pressure on the outer wall, a rupture occurred.

Bulging and herniated disc can occur anywhere in the spine, but most commonly occur in the lumbar and cervical spine. Both bulging discs and herniated discs can lead to irritation of the surrounding spinal nerve roots, which can result in back pain as well as numbness, tingling, and weakness of the extremities.

Causes Of Bulging And Herniated Discs

The most common cause of bulging and herniated discs is degenerative change that occurs with aging. The intervertebral discs lose water content with age, making them less flexible and far more susceptible to damage. However, both conditions can also be caused by acute, traumatic events including a slip and fall, sports injury, or motor vehicle accident.

Various risk factors have been identified which increase the risk of disc bulging or herniation. These risk factors include:

  • Excess weight
  • Smoking
  • Working in an occupation that requires heaving or repetitive lifting, bending, or twisting
  • Family history of intervertebral disc disease

Treatments For Bulging And Herniated Discs

Before initiating treatment, a physician will perform a history and physical examination on a patient presenting with symptoms of an intervertebral disc disorder. The history will include questions related to the patient’s past medical history and family history, as well as to their current condition. The physical examination may include inspection and palpation of the affected area, orthopedic testing, muscle testing, reflex testing, and sensation testing.

While most bugling and herniated discs can be diagnosed with a history and physical exam, additional imaging tests including X-ray, magnetic resonance imaging (MRI), and computer tomography (CT) may be ordered to rule out underlying pathology as well as to confirm the spinal level that is affected by the disc disorder. If nerve impairment is suspected, a nerve conduction test may also be ordered. While bulging discs and herniated discs are two distinct conditions, they result in similar pain patterns and are therefore treated in the same manner.

First-line pharmacologic treatment usually begins with analgesic and anti-inflammatory medications, as well as muscle relaxants. If these medications fail to provide adequate pain relief, narcotics may be prescribed for a short period of time. In some patients, the use of antidepressants may also be warranted.

Epidural corticosteroid injections or nerve blocks may be recommended. Epidural corticosteroid injections involve injecting a corticosteroid and a local anesthetic into the epidural space. The corticosteroid helps to reduce inflammation, while the anesthetic helps to numb the affected area. Nerve blocks involve injecting the medication directly into the affected nerve root, which helps to block pain sensation.

Alternative treatment options that may provide pain relief for some patients include physical therapy and chiropractic care. These treatments involve the use of various modalities including manual therapy, which may involve spinal manipulation, in addition to cold or hot compresses, ultrasound, electrical stimulation, and exercise therapy.

Patients who continue to experience pain even after undergoing conservative treatments may be advised to consider surgical intervention. Additionally, patients who have bowel or bladder incontinence as the result of a bulging or herniated disc need to undergo spinal surgery. In the case of bulging and herniated discs, the most common surgical procedure performed is a discectomy. This procedure involves the removal of damaged disc material. If the entire disc is removed, a spinal fusion procedure, which connects vertebrae, may be needed to ensure spinal stability.


The terms bulging disc and herniated disc are often used interchangeably to describe intervertebral disc disorders. However, there is a distinct difference. A disc bulge is a contained disorder, whereby no disc material has leaked from the intervertebral disc. Conversely, a herniated disc is a non-contained disorder, whereby part of the nucleus pulposus has leaked from the intervertebral disc into the spinal canal. It is even possible that a piece of the disc breaks off and drifts into the spinal canal. Bulging discs as well as herniated discs can cause back pain as well as extremity pain, numbness, tingling, and weakness. While the severity of symptoms differs among patients, treatment is often necessary to alleviate symptoms to improve a patient’s quality of life.

Treatment for bulging and herniated discs is the same and usually begins with analgesic and anti-inflammatory medications, as well as muscle relaxants. Additional drugs that may be prescribed include narcotics and antidepressants. Other options for pain control include epidural steroid injections and nerve blocks. Alternative treatment options, including physical therapy and chiropractic treatment, may also be beneficial. Surgery may be necessary for patients who suffer from pain that is non-responsive to conservative treatment measures.


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