What is spinal stenosis, and what causes it?

Stenosis means “narrowing.” With spinal stenosis, the opening or “canal” through which the spinal cord passes is too small for the cord. This can happen anywhere in the spine, but it happens most often in the low back. The neck is the second most common location for spinal stenosis.


There are many possible causes of spinal stenosis. The first is the structure of bone or size of the opening at birth. This is called primary stenosis. More common is secondary stenosis, which is caused by the aging process. Sometimes bony growths called osteophytes form and block the spinal canal.


Changes in the disc material between the bones of the spine may contribute to stenosis. These changes start with the disc and affect the surrounding ligaments and joints. The final result is to narrow the opening of the spinal canal.


Finally, trauma from a car accident, fall, or other injury can cause damage to the spine and surrounding structures. This can also lead to stenosis.