Secondary (acquired) stenosis arises from degenerative changes, iatrogenic causes, systemic processes, and trauma. Degenerative changes include central canal and lateral recess stenosis from posterior disk protrusion, zygapophyseal joint and ligamentum flavum hypertrophy, and spondylolisthesis.

Iatrogenic changes happen after following surgical procedures such as laminectomy, fusion, and discectomy. Systemic processes that may be involved in secondary stenosis include Paget disease, fluorosis, acromegaly, neoplasm, and ankylosing spondylitis. The central canal and the neurorecess may be compromised by tumor infiltration, such as metastatic disease of the spine, or by infectious spondylitis. An abscess may directly compress the spinal cord if it is contained in the epidural space, while discitis and vertebral osteomyelitis may compress the canal following the vertebral collapse. Paget disease results in spinal stenosis as a result of enlargement of the vertebral body, while idiopathic ossification of the posterior longitudinal ligament directly narrows the central spinal canal, most often in the cervical or thoracic regions.