With age, the joints of the vertebrae wear down, triggering a contraction of the spinal canal. This condition is known as stenosis, wherein the narrowed spinal canal puts pressure on the surrounding nerves and causes weakness in the limbs.

Since stenosis is a progressive condition, it may be asymptomatic as well. About 95% of patients who have stenosis also have sciatica.

• Pain that radiates down the leg (same as in sciatica)
• Cramping in the arms and legs, along with general pain
• Neck pain or back pain
• Foot drop: The weak leg causes the foot to slap against the ground
• Numbness, tingling, and weakness in the limbs
• Pain reduces while sitting and increases when upright
• Bowel and bladder dysfunction

The patient experiences radiating pain in the limbs depending upon where the stenosis is, and about 70% of the patients complain of sensory changes in the arms and legs.

Stenosis Causes

Stenosis occurs due to normal wear and tear associated with aging, and usually affects people over 50. Other causes of spinal stenosis are:

• Rheumatoid or osteoarthritis.
• The soft gel inside the vertebrae leaking through a herniated disc and putting pressure on the surrounding nerves
• Bone spur: An overgrowth of the bone pinching the nerve in the spinal canal.
• Thickening ligaments: Due to aging, the ligament thickens and bulge into the spinal canal.
• Having a small spinal canal
• A tumor in the spinal canal, reducing its size
• Degenerative scoliosis: The spine bends sideways and the spinal canal has reduced space
• Spondylolisthesis: one vertebra slips forward on another
• Injuries that dislocate the spine

In very rare cases, people are born with stenosis.