Lumbar (low back) spinal stenosis is often the result of the aging
process, which over time causes the soft tissues and bones in the spine to
harden or grow excessively. These changes may narrow the spinal canal and put
pressure on the spinal nerve roots. Spinal stenosis is seen
most often in adults older than age 50.
Some people develop spinal stenosis because of back problems they are
born with. This is known as congenital spinal stenosis. Symptoms of congenital
spinal stenosis are often first noticed before age 40.