Spinal stenosis happens when the space inside the backbone is too small. This can put pressure on the spinal cord and nerves that travel through the spine. Spinal stenosis occurs most often in the lower back and the neck.

Some people with spinal stenosis have no symptoms. Others may experience pain, tingling, numbness and muscle weakness. Symptoms can get worse over time. The most common cause of spinal stenosis is wear-and-tear changes in the spine related to arthritis. People who have severe cases of spinal stenosis may need surgery.

Surgery can create more space inside the spine. This can ease the symptoms caused by pressure on the spinal cord or nerves. But surgery can’t cure arthritis, so arthritis pain in the spine may continue.

Causes

• Herniated disks. Disks are the soft cushions that act as shock absorbers between your spinal bones. If part of the disk’s soft inner material leaks out, it can press on the spinal cord or nerves.
• Thick ligaments. The strong cords that help hold the bones of your spine together can become stiff and thick over time. Thick ligaments can push into the spinal canal.
• Tumors. Rarely, tumors can form inside the spinal canal.
• Spinal injuries. Car accidents and other trauma can cause spinal bones to break or move out of place. Swelling of nearby tissue right after back surgery also can put pressure on the spinal cord or nerves.