Understanding Herniated Discs

A herniated disc occurs when the soft, gelatinous inner core of a spinal disc leaks out through the disc’s weakened outer layers and affects a nearby nerve.

To help you clearly visualize how a disc herniates and creates pain, we've created this Telly Award-winning animated video.

See What's a Herniated Disc, Pinched Nerve, Bulging Disc...?

Herniated Disc VideoWatch this animated 2-minute video to clearly visualize what happens when a disc herniates: Herniated Disc Video

Herniated disc video highlights

Each vertebra in your spine—shown below in white—is separated from the next by a spinal disc.

These discs allow for flexibility and movement of the spine, absorbing shock when you move. In the image below, each disc is shown in blue.

Spinal Discs Spinal discs act both as shock absorbers between vertebrae and as ligaments that hold the spine together. See Spinal Discs
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Degeneration over time or due to forceful trauma may cause weak spots to form in the outer layers (the annulus fibrosus) of a spinal disc, as shown below.

See Degenerative Disc Disease Progression over Time

Weakened Spinal Disc Spinal discs act both as shock absorbers between vertebrae and as ligaments that hold the spine together. See Understanding the Clinical Diagnosis of a Herniated Disc

When weakening of the annulus fibrosus occurs, the soft, gelatinous center (the nucleus pulposus) of the disc can leak out.

Disc Leakage When the nucleus pulposus breaks through the weakened annulus fibrosus, the nerves near the spinal disc can be compressed or irritated. See Understanding the Clinical Diagnosis of a Herniated Disc

When a nerve is compressed by the nucleus pulposus, the herniated disc may begin to become symptomatic.

A closer look at lumbar herniated discs

Your lumbar (lower) spine carries more weight than your thoracic spine (found in the middle and upper back) or cervical spine (found in the neck) and is particularly susceptible to injury.

Lumbar Spine Segments The three lowest discs in your lumbar spine, labeled here as L3-L4, L4-L5, and L5-S1, are the most prone to injury. See Lumbar Spine Anatomy and Pain

If your lumbar herniated disc has pinched a nerve, you may experience pain moving down your buttock and into your leg. This type of pain is often referred to as sciatica.

In rare instances, a lumbar herniated disc may cause you to lose control of your bowel or bladder. This lapse of control may be a sign of cauda equina syndrome, a relatively rare but serious medical condition involving dramatic swelling of the nerves at the end of the spinal cord.

See Lumbar Herniated Disc: What You Should Know

A closer look at cervical herniated discs

The cervical spine is found in the neck. Cervical herniated discs are less common than lumbar herniated discs, and are most frequent among people between the ages of 30 and 50.

When a disc in your cervical spine herniates, it can put pressure on an adjacent nerve root, which may cause pain to move along the nerve pathway down your arm.

See Cervical Spine Anatomy and Neck Pain

Disc Herniation A cervical herniated disc can impinge on a nerve root, as shown above, and potentially cause cervical radiculopathy. Watch: Cervical Herniated Disc Video

The pain and neurological symptoms you experience from a cervical herniated disc will depend on the severity and location of the herniated disc.

For example, a cervical herniated disc near the upper middle of your cervical spine (C4-C5) could cause shoulder pain and weakness in your upper arm. A cervical herniated disc at the bottom of the cervical spine (C7-T1), though, might cause numbness, weakness in the grip of your hands, or a painful, tingling sensation that moves down the arm to the outside of your hand, near your little finger.

See Cervical Herniated Disc Symptoms and Treatment Options

A closer look at thoracic herniated discs

While less common than lumbar disc herniations, the discs in your thoracic spine (the upper back) can also herniate.

Upper Back Pain A thoracic herniated disc may cause upper back pain, abdominal pain that radiates through your chest wall, or both. Watch: Thoracic Herniated Disc Video

Symptoms of a thoracic herniated disc will correlate with the location of your disc herniation. Thoracic discs can herniate centrally (move backward into your spinal canal), laterally (move to the side of your spine), or centro-laterally (move both backwards and sideways).

See Thoracic Disc Herniation Symptoms

If you have a central herniation in the thoracic spine, you’re likely to experience upper back pain and, in rare cases, myelopathy, a compression of the spinal canal in your upper back. Lateral thoracic herniated discs are likely to cause abdominal pain or pain radiating through your chest wall, while centro-lateral herniations of the cervical spine commonly cause upper back pain and radiating chest wall pain.

Learn more:

Treatment Options for a Herniated Disc

Understanding the Clinical Diagnosis of a Herniated Disc

Post written by Daniel Perret