What causes sciatica pain?
As noted above, the leading cause of sciatica has to do with an unnatural compression of the sciatic nerve. Most commonly, sciatica is caused by a herniation of the spinal discs. Other possible causes include displacement of a vertebra, pelvic tumors, and pregnancy.
As you can see, we can’t understand sciatica pain without studying the spine and spinal problems. In most cases, patients with sciatica pain also experienced low back pain for three months or more. Their back pain diagnosis can be nonspecific, but they could have a hidden disk degeneration or herniation.
When a degenerative change occurs in the intervertebral discs, this sponge-like structure loses its capacity to cushion the vertebrae. The spaces between vertebrae narrow down, and the spaces where nerves come out of the spinal cord are smaller. This creates compression of the spinal cord, and if the sciatica nerve is involved, we will experience sciatica pain.
However, this is only theory, and the real world is a bit more complex. Sometimes we can see patients with significant degenerative changes in the spine but no pain whatsoever. Other patients do not display any degenerative change or just a mild problem, and they have severe sciatica pain. Thus, the mechanical causes of sciatica are sometimes not enough, and other factors should be considered. They are known as inflammatory or biochemical pathways.
Inflammation is a natural response to defend the body against invaders, but it sometimes turns against us. Cytokines released by white blood cells change the way blood vessels work and cause edema. This creates mechanical pressure upon the surrounding structures and may trigger pain. But cytokines also activate nerve terminals and cause pain without any intermediates. That is why anti-inflammatories are very useful to relieve a headache or the pain you feel after trauma.