Lumbar spinal stenosis occurs when the open spaces within your spine narrow, which can put pressure on your spinal cord and the nerves that travel through the spine. While some people have no signs or symptoms, spinal stenosis can cause pain, numbness, muscle weakness, and problems with bladder or bowel function.
Spinal stenosis is most commonly caused by wear-and-tear changes in the spine related to aging. As people age, the soft tissues and bones in the spine may harden or become overgrown. These degenerative changes may narrow the space around the spinal cord and result in spinal stenosis.