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.
Spinal stenosis often causes no symptoms. When symptoms do occur, they start slowly and get worse over time. Symptoms depend on which part of the spine is affected.
In the lower back
Spinal stenosis in the lower back can cause pain or cramping in one or both legs. This happens when you stand for a long time or when you walk. Symptoms get better when you bend forward or sit. Some people also have back pain.
In the neck
Spinal stenosis in the neck can cause:
- Tingling or weakness in a hand, leg, foot or arm
- Problems with walking and balance
- Neck pain
- Problems with the bowel or bladder
Spinal bones are stacked in a column from the skull to the tailbone. They protect the spinal cord, which runs through an opening called the spinal canal.
Some people are born with a small spinal canal. But most spinal stenosis occurs when something happens to reduce the amount of open space within the spine. Causes of spinal stenosis include:
- Bone spurs. Wear-and-tear damage from arthritis can cause extra bone to grow on the spine. These are called bone spurs. They can push into the spinal canal. Paget's disease also can cause extra bone to grow on the spine.
- 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.
Most people with spinal stenosis are over age 50. Younger people may be at higher risk of spinal stenosis if they have scoliosis or other spinal problems.