What causes spinal stenosis?

Several things: Spinal stenosis can be congenital but is also acquired with aging, or trauma, by either arthritis, herniated discs or even vertebral collapse as people age, which can result in vertebra slipping across each other which can cause stenosis too. It is important to see a neurosurgeon for evaluation, or a orthopedist who specializes in the spine, for full evaluation and treatment, surgery is an option.

Many: Some are born with. Some get herniated disk, spondylosis, tumor etc.

Several causes: People are born with either a small, medium or large spinal canal. Spinal stenosis is when the canal is too narrow fornerve tissue resultting in its compression. Everyone's canal narrows with time due to degeneration. By age 60, 20% have imaging finding of stenosis but not necessarily symptoms. Other causes are: congenital v acquired due to - fracture, herniation, tumor, fat, instability.

Degeneration: It is typically a degenerative, arthritic process in the spine.

You can't: The size of the canal is inherited. The secondary degenerative leading to further narrowing is also linked to genetics. You may be able to reduce this by healthy living (regular exercise, no tobacco use, etc), but overall you have little influence on this condition.

Born with or develop: Spinal stenosis is a narrowing of the spinal canal leading to compression of nerve tissue. You can be born with it or you can develop it with age related or degenerative changes or acquire it through deformities/instabilities or with disc herniations, synovial cysts or after some spine fractures.

Spinal stenosis.: Spinal stenosis in a condition wherein tissue grows around the spinal cord, causing gradual compression and pain. It's progressive and unrelenting. Unfortunately leading to debility and pain. Surgical options are available which may help, but left alone it'll cause progressive limitations. The rate of progression is unpredictable.

Degeneration: The most common type is caused by a gradual, progressive arthritic process in the spine.