The sciatic nerve is the largest and longest nerve in the body. It starts in the lumbar (lower back) region of the spine and travels down the leg to the foot. The nerve has the important job of supplying the thighs, lower legs, and feet with nervous system intervention. When the nerve is compressed or pinched at the vertebral level, a symptom known as sciatica may occur.
Describing SciaticaSciatica is typically only experienced on one side of the body. It presents in the buttocks, back of the thigh, calf, and/or feet as a burning, tingling, and/or numbing pain. Weakness may also present. Because a detailed description of symptoms gives an spine specialist important clues regarding their cause, patients are encouraged to monitor their symptoms and make notes when they present.
Causes of SciaticaSciatica may be caused by a variety of lower back conditions. The three most common include the following:
- Lumbar spinal stenosis. The lumbar vertebrae perfectly align to form a canal that the spinal cord travels through. Lumbar spinal stenosis occurs when the canal narrows and compresses the cord.
- Lumbar disc herniation. Between each lumbar vertebra lie intervertebral discs. The discs protect the vertebrae by acting as load distributing cushions or “shock absorbers”. When a disc herniates or slips, it may protrude into the spinal canal and compress or pinch the spinal cord.
- Degenerative disc disease. A chronic condition characterized by the degeneration of vertebral bone and soft tissue due to aging processes. Degenerative disc disease is typically a precursor to lumbar spinal stenosis or a lumbar disc herniation.