Spinal stenosis is the narrowing of the spinal canal caused by excessive bone growth, thickening of tissue in the canal (such as ligaments or cartilage), herniated disc, or all three. This narrowing can squeeze and irritate the spinal cord itself or the spinal nerve roots where they leave the spinal cord.

The main cause of spinal stenosis is the breakdown (degeneration) of tissues caused by the normal aging process. Symptoms of spinal stenosis most often occur in people older than age 50.

Spinal stenosis occurs most often in the lower back (lumbar) area and can cause pain, numbness, or weakness in the legs, feet, or buttocks. Some people experience low back pain. These symptoms get worse when the back is stretched or extended, such as when a person is walking in a flat area or downhill, standing straight, or leaning backwards. The pain gets better when the spine is flexed forward, for example, when a person is sitting down, leaning over a grocery cart, or walking uphill.

Stenosis in the neck area is called cervical stenosis. It can cause stiffness, pain, and numbness in the neck, arms, and legs, as well as problems with bowel and bladder control (incontinence). If cervical stenosis is untreated, it can squeeze and injure the spinal cord itself and lead to nerve damage and paralysis.

Symptoms can often be controlled using pain-relief medicine, strength and flexibility exercises, physical therapy, or corticosteroid injections. Surgery may be considered for symptoms that are severe, are getting worse, or that restrict normal daily activities.