Spinal stenosis is the abnormal narrowing of the spinal or vertebral canal. There are quite a few medical conditions which can lead to this narrowing. Read on, to know about the various causes of this condition in an individual.

Spinal stenosis is a medical condition that affects the spine. In this condition, the spinal canal containing the spinal cord and spinal nerves becomes narrow at one or more places in the spine. This narrowing results in compression of the spinal cord and nerves, thereby affecting them adversely. The pressure buildup compress the nerves either at points where they exit the spinal cord and run to various parts of the body, or within the spinal cord. This compression hampers the normal functioning of these nerves in the body. Signals sent to and from the brain may turn abnormal because their transmission fails at the point of compression. This results in weakness, pain, and numbness in patients suffering from spinal stenosis. There is no single reason behind the occurrence of this problem, but a multitude of factors that can cause this condition in the body. Let's have a look at them.

Causes of Spinal Stenosis

Aging
As people get older, many changes occur in the body. Aging can result in the enlargement of bones and joints, thickening and hardening of supporting tissue of the spine, and bone spurs which are protruding bone surfaces. All these changes can affect the spine and lead to narrowing of the spinal canal. Aging is one of the most common causes of this clinical condition.

Arthritis
Some patients suffering from arthritis are known to develop spinal stenosis. Patients with rheumatoid arthritis are less likely to develop this problem because this cause of spinal stenosis is not very common. In rare cases, when this form of arthritis is the cause, the tissues surrounding the joints swell and damage the internal organs. The severity of damage to joints is quite high in case of rheumatoid arthritis. Patients with osteoarthritis suffer from deterioration of vertebral joints. This deterioration triggers the body to form bone spurs which are bony growths in the vertebrae. These growths lead to narrowing of the spinal canal thus, causing spinal stenosis. Besides these, ankylosing spondylitis, the chronic form of arthritis may also lead to the precipitation of this problem in patients.

Spondylolisthesis
Spondylolisthesis is a condition pertaining to the instability of spine. Due to instability, a vertebra slips over the one situated below it. This slippage may sometimes be critical enough to induce spinal stenosis due to narrowing of the spinal canal, and compression of nerves present in that region. The fourth and fifth lumbar vertebrae are usually affected by spondylolisthesis in adults. In children, the fifth lumbar vertebrae and the first bone in the sacrum area are affected.

Degeneration of Spinal Disk
Vertebrae have a layer of cushioning between them to prevent any kind of damage. As a person grows old, this cushioning becomes flat and bulges out. With time, the protective covering of the disk is also damaged with small tears. This leads to the protrusion of jelly-like substance which is present at the center of the disk. This often compresses the spinal nerves.

Achondroplasia
Young people can also develop spinal stenosis due to this genetic disorder. This disorder affects an individual right from the fetal stage to childhood, and decreases the rate of bone growth. Due to slow formation of bone, narrow spinal canal is formed resulting in stenosis at a younger age. It also leads to dwarfism in such children.

Thick Ligaments
Ligaments are fibrous tissue that connect one bone to the other. These structures are very tough and capable of holding bones together. With aging, these ligaments become thick and develop reduced flexibility. Thickened ligaments that join vertebrae can form a bulge in the spinal canal and narrow it down, thereby pressing the nerves located in that area.

Paget's Disease
This medical condition is associated with fast development of new bone at a rate higher than normal. This generation can occur in any part of the body. If it affects the spine, it may lead to spinal stenosis. When the body starts generating new bone at a faster pace, it is unable to build strong bones. The new bones are rather weak and soft, and can grow larger than normal or get deformed. The deformed bones of the vertebral column can affect the nervous tissue of the spinal canal.

Fluorosis
Fluorides can cause calcification of ligaments joining the spinal bones together. Due to this, spinal ligaments may thicken and harden leading to spinal stenosis. People living in areas where the environment is polluted with high fluoride content, or receive water containing fluorides are generally affected by fluorosis, i.e., excess level of fluorides in the body.

Injury
Spinal injuries or accidents can affect the spine in a really bad way causing dislocation of vertebrae. Dislocation can also be accompanied by fractures which can worsen the condition. This can damage the spinal cord and nerves causing spinal stenosis. Post-surgery trauma often causes inflammation of tissue surrounding the spine, which can also be a potential cause of stenosis in the spine.

Tumors
The spine is also affected by tumors. They can form at any part of the spine and compress the nervous tissue in that area. Tumors are mostly found between the spinal cord and vertebrae. They can also form within the spinal cord or inside the membranes covering the cord. Sometimes, the tumor can migrate from other part of the body where it has proliferated.

Heredity
Inherited conditions can sometimes result in spinal stenosis at a much younger age. A person may have a narrow spinal canal right from birth due to heredity. This surely increases the chances of developing stenosis in such individuals. People born with scoliosis or curved spine are also prone to develop this spinal problem at some point in life.

Apart from the above mentioned causes, conditions like Ossification of the Posterior Longitudinal Ligament (calcification of posterior longitudinal ligament situated in the spinal canal) and Diffuse Idiopathic Skeletal Hyperostosis (calcification of ligaments at the point of attachment to spine) also lead to spinal stenosis. Patients suffering from spinal stenosis are treated with medications or surgery. Lifestyle changes like taking extra care to avoid injuries, exercising, and losing weight can reduce the discomfort and pain associated with this problem. Walkers for lumbar stenosis, and hot or cold packs for cervical stenosis can also be used to relieve patients suffering from this condition.