What is a Herniated Disc?

Animation of a herniated disc

A herniated disc happens when the inner disc material, called the nucleus, seeps through the tough outer wall of the disc. It becomes symptomatic when it comes into contact with surrounding nerves causing pain and other herniated disc symptoms to be felt locally and along the nerves path.

There are three main types of herniated discs:

Contained Disc Herniation:
The disc is considered contained if the inner material of the disc has not pushed through its outer wall. It is also sometimes referred to as a contained disc herniation.
Extruded Disc Herniation:
The disc is considered extruded if the inner material has broken through its outer wall but is still attached to the disc. It is also sometimes referred to as an extruded disc herniation.
Sequestered Disc Herniation:
If the nucleus has pushed through the annulus and broken away from the disc it is known as a sequestered disc.

Is There a Difference Between a Herniated Disc in the Back and a Herniated Disc in the Neck?

The only difference between a herniated disc in the back and a herniated disc in the neck is that the first will give you pain and symptoms in the neck, shoulder, and arms, while the other will present with symptoms in the lower back, buttocks, legs, and feet.

doctors note

Note From Dr. Liu:

Exercise can help strengthen core muscles that help to stabilize and support the spine.

Healthy Disc Compared to a Disc Herniation

In a healthy disc (1a.) you can notice that the outer wall is thick and tough. As disc degeneration starts to set in this wall will start to thin and dry out allowing for the possibility of cracks or tears. Once a tear or a crack occurs the disc can herniate (1b.) as the inner materials come through and places pressure on surrounding structures.

Healthy Vertebral Disc
Figure 1a. Healthy strong vertebral disc.
herniated disc compressing a spinal nerve causing back pain
Figure 1b. Extruded disc with the nucleus broken through outer wall touching nerves.