of the vertebrae may cause narrowing of the spinal canal.

Aging

Any of the factors below may cause the spaces in the spine to narrow.
* Spinal ligaments can thicken (ligamenta flava)
* Bone spurs develop on the bone and into the spinal canal or foraminal openings
* Intervertebral discs may bulge or herniate into the canal or foraminal openings
* Degenerative disc disease