Many people older than age 50 have some narrowing of the spinal canal (spinal stenosis) but do not experience symptoms. If the nerve roots or spinal cord become squeezed, symptoms may include:

• Numbness, weakness, cramping, or pain in the legs, feet, or buttocks. These symptoms get worse when you stretch or extend your back, such as when you walk, stand straight, or lean backwards. The pain gets better when you flex your spine forward, such as when you sit down or lean over a grocery cart.
• Stiffness in legs and thighs.
• Low back pain.
• In severe cases, loss of bladder and bowel control.

Since the nerve roots that pass through the lower (lumbar) spine extend to the legs, spinal stenosis most commonly affects the legs. The classic symptom of lumbar spinal stenosis is leg pain when walking and standing that is relieved by sitting. Leg pain is often present when the spine is extended, as while standing straight or leaning backwards, and is relieved when the spine is flexed, as in a sitting position or when walking uphill or leaning over a grocery cart. Some people find bicycling more comfortable than standing or walking. People with severe lumbar spinal stenosis may develop a habit of leaning forward in a stooped position to relieve symptoms.

See an illustration of nerves commonly affected by spinal stenosis.

In some cases, the severity of symptoms may not relate to the degree of the narrowing of the spinal canal as seen on imaging tests. You may have very severe symptoms, but tests show relatively little narrowing of the spinal canal. Or you may have mild symptoms, but tests show a significant narrowing of the spinal canal. Therefore, treatment is based not only on imaging test results, but also on the severity of symptoms and their impact on your normal daily activities and quality of life.

Several other conditions have symptoms similar to spinal stenosis.