The Science of Sciatica Pain

The Science of Sciatica Pain

A few years ago, I suffered from a herniated disc. The pain in my lower back was horrible, misery-inducing and relentless. And then the sciatica started. A pulsing shot of pain traveled down the back of my leg. I couldn’t sit comfortably. I couldn’t stand comfortably. The sciatica only lasted one week—compared to the years it took for the herniated disc pain to subside—but the memory of that radiating pain is still so clear that I remember where I was the very first time I felt it.

Sciatica is caused by compression on a nerve, most commonly in the spine, explains Bartosz Wojewnik, MD, an orthopedic surgeon at Loyola University Medical Center. The sciatic nerve, which runs from the lower spine all the way down to the feet, is the largest and longest nerve in the human body. It is part of a network of nerves that occupy and surround the spinal area, pelvis and leg.

Compression on the nerve can cause pain, tingling, numbness or weakness. It commonly occurs in response to spinal injuries, like herniated discs, bony spurs, bulging discs or pelvic injuries, but it can also be attributable to other changes in the structure of the spine.

“As we get older, the discs flatten out, and there can be some arthritis,” says John Prunskis, MD, FIPP, medical director of the Illinois Pain Institute. “Those processes together can decrease the size of the opening where the nerves comes out of the spine, so the nerves get irritated.” In other cases, sciatica can be caused by spinal tumors or a number of other disorders that directly affect the spinal area.

Sciatica is diagnosed in a multistep process. Doctors start with the patient’s history and try to pinpoint exactly where pain, numbness or feelings of weakness are occurring. The next step is a physical examination, another helpful tool in locating where the nerve is irritated. Finally, a doctor may do X-rays, a nerve-conduction study or an MRI scan.

“What we’re looking for [when we do an MRI scan] are any abnormalities in the spine itself, such as a disc that’s pushing out of the spinal column and rubbing on a nerve,” Prunskis says. Doctors also look for signs of arthritis, bony spurs, disc abnormalities or other pathological conditions—all of which are spinal issues that can lead to sciatica.

A diagnosis does not always lead to aggressive treatment. “Typically it’s just a matter of your body healing whatever the irritation is,” Wojewnik says. “Usually after a week or two you’re going to start seeing some improvement without any treatment.”

During this initial period, doctors will generally recommend over-the-counter anti-inflammatory drugs like ibuprofen, sometimes in conjunction with Tylenol, to make patients more comfortable while their bodies heal themselves. If necessary, physicians will give patients an epidural steroid injection at the point of nerve inflammation to decrease swelling and help facilitate healing.

Depending on the exact cause of the sciatica and the duration of pain and weakness, surgery may be the recommended course of treatment, though only a limited number of patients end up needing to go this route, Wojewnik says.

Want to decrease your chances of developing sciatica? Prunskis says to watch your weight, strengthen your abdominal core, use proper lifting techniques and perform stretching exercises as a means to better support your back. Also, put down the cigarettes, which inhibit the healing processes of the back and spine. If you do notice persistent pain, tingling, numbness or slight weakness in your leg, you can give your body a week or two to heal on its own before needing to see a doctor. If it’s a profound weakness, however, Prunskis says you need to see a doctor immediately.

Originally published in the Spring 2016 print edition.