A herniated disc can occur as a result of aging, injury, or both. Due to the complex system of nerves surrounding the spinal discs, even a minor herniation can cause debilitating pain.
To help you better understand how a disc herniation occurs, here is a step-by-step visual walk through of the process.
The spinal disc sits in between two vertebrae. Each disc has two primary components:
- The nucleus pulposus, a softer, gel-like substance in the center of the disc.
- The annulus fibrosus, which consists of several of the disc’s outer layers
Read more: Spinal Discs
In addition to supporting the vertebrae, each spinal disc helps to facilitate movement. When this structure degenerates, disc herniations are more likely to occur.
Degeneration starts when layers of the annulus fibrosus weaken.
If the annulus fibrosus weakens enough, eventually the nucleus pulposus may seep out past the annulus fibrosus and affect a nearby nerve, which is when it starts to cause symptoms.
In the case of a lumbar herniated disc, a spinal nerve root sits just above the location where the annulus fibrosus commonly weakens. When the disc herniates, the nucleus pulposus can put direct pressure on the nerve root.
This pressure on the nerve root causes pain, numbness, weakness, or tingling sensations down the leg along the nerve path. This is known as sciatica pain.
Read more: What You Need to Know About Sciatica
Everyone experiences a herniated disc differently. Some individuals may have a herniated disc and experience no symptoms, while others may have severe sciatica pain from a relatively small disc herniation.