The spinal cord is a nerve bundle that sits within and protected by the spine2. It serves as the primary pathway of sensory and motor signal transmission to and from the brain. As such, it is a delicate and sensitive tissue.
Damage to the spinal cord can have far-reaching effects, including pain, paralysis of the muscles, and decreased organ function. The spinal cord is able to heal, slowly. Because of this, many cases of sciatica can be treated and resolved.

One primary cause of sciatica is a herniated disc3. Between each bone in the spinal column, there are cushioned discs that keep proper spacing in the spine and provide support during impact to keep the bones from rubbing up against one another.
Herniated Discs
During normal, gentle movements this is not an issue and the spinal disc is able to absorb the shock. However, when excessive force is placed upon any particular spinal disc, it can cause that disc—perhaps best described as a semi-solid get—to compress and displace, usually by bulging out.
This is known as a herniation.

There are a number of situations that can result in disc herniation. The spine can essentially perform 3 motions- forward and backward flexion, side to side lateral flexion, and rotational twisting.
When one of these motions is overdone, it stresses the entire spine. Depending on personal medical history, the angle that the activity is performed, and current health, certain spinal portions can be especially vulnerable.
Another potential cause of herniation comes from overexertion. While overextension puts pressure on a segment of the spine in motion, the spine can also only properly carry loads of a certain weight.
This “breaking point” will vary based on age, strength, and activity level. Posture also plays a major role in performing heavy work activities like lifting heavy loads or pushing and pulling heavy objects.
The proper ergonomic alignment will allow for maximal strength with minimal risk of injury.

We all have heard to “lift with our legs, not with our back.” When we do primarily use our back to lift, the pressure of the load is focused on the spine, which is not designed to bear this kind of burden.
This can result in a herniation.
Finally, herniations can be caused by impact or sudden, external forces. While you can actively twist too far and hurt your back, it can be even more damaging when you are twisted by some outside object. The unexpected impact of a car accident or other similar injury can also lead to a disc herniation.
When the body moves quickly and unnaturally, the built-in mechanisms to protect the spine are not able to correct position in time to prevent an injury.
When the intervertebral disc is herniated out of place, it is no longer able to effectively do its job and support the spine. Because of this, spinal herniations put additional pressure on the spinal cord. This added pressure can result in pain, numbness, and a loss of motor control.
Depending on the location of the disc herniation, exact symptoms will differ based on the affected nerves. Since the precise nature of sciatica can change depending on the amount of pressure put on the spinal cord and the location, no two people will have the exact same experience with sciatica.
Herniations are recognized as a common cause of sciatic pain but are not the only possible cause4. Other common causes include age-related narrowing of the spine, or less commonly bone spurs or tumors can put pressure on the sciatic nerve. Regardless of the cause, the treatments mostly focus on one key principle—reducing pain and inflammation.