Learn more about sciatica and its most common causes as well as their role in creating the pain and other symptoms that can be felt anywhere from your lower back all the way down to the soles of your feet.
Symptoms of sciatica develop when some part of the nerve becomes irritated, compressed (or “pinched”), or inflamed. Symptoms develop depending on where and why the nerve is affected.
Sciatica typically involves pain that radiates down one leg from the lower back to below the knee. But it can also cause achiness, numbness, a burning sensation, tingling, or jolts of pain anywhere along the nerve’s path. Symptoms vary in intensity from one episode to another and can range from mild to severe.
Anything that affects the sciatic nerve, such as trauma or illness, can trigger symptoms of sciatica. But by far the two most common causes are:
A bulging or herniated disc in the lower backSpinal stenosis
You could be at risk if you have a job that requires you to sit for long periods (either at a desk or behind the wheel) or if you do a lot of heavy lifting with frequent twisting and bending. If you have diabetes, you are more vulnerable. Cigarette smoking can also contribute to degenerative changes in the spine that heighten sciatica risk.
Disks are shock-absorbing, round “cushions” that lie between each of the bones in the spine (the vertebrae). When the jelly-like tissue inside a disk bulges through its protective covering or pushes its way out between two vertebrae, it can put pressure on surrounding spinal nerves and trigger symptoms of sciatica.
Slipped disks in the lower back usually affect the vertebrae in the lower part of the spine. This area, called the lumbar region, is in close proximity to the sciatic nerve.
The same processes that cause bony damage over time can also affect the spinal ligaments that hold vertebrae in place. These ligaments can eventually swell, leading to a smaller spinal canal and nerve impingement.
Traumatic injury, such as a pelvic fracture Vertebrae that are misaligned (spondylolisthesis) Excess weight or weight gain during pregnancy, which puts pressure on the sciatic nerve Cancers that compress the sciatic nerve if they spread to the spine or pelvis Cysts or abscesses on or near the spine Muscle spasm or inflammation Paget’s disease (which causes bony overgrowth) Piriformis syndrome, in which a too-tight piriformis muscle in the buttocks constricts the underlying sciatic nerve
