Spinal stenosis: Narrowing of the spinal canal. Spinal stenosis is most commonly caused by degeneration of the discs between the vertebrae. The result is compression of the nerve roots or spinal cord by bony spurs or soft tissues, such as discs, in the spinal canal. This most commonly occurs in the low back (lumbar spine) but can also occur in the neck (cervical spine) and less frequently in the upper back (thoracic spine). The symptoms of spinal stenosis vary depending on the location on the nerve tissues being irritated and the degree of irritation. The neck being affected can result in unusual sensations in the arms and/or poor leg function and incontinence. When the low back is affected, the classic symptom is pain that radiates down both legs while walking and is relieved by resting (pseudoclaudication). If symptoms of spinal stenosis are mild, conservative measures designed to relieve the nerve irritation are taken, such as using medications to relieve inflammation, using mechanical supports, and doing back exercises. When symptoms are severe, persistent, and intolerable, surgical resection of the bone and soft tissues that are impinging on the nerves and/or spinal cord can be helpful.