Causes of Sciatic Nerve Pain - Sciatica
Sciatica is the condition of sciatic nerve inflammation. To learn more about the anatomy of the sciatic nerve visit my page called Sciatica - Getting to the Root of the Problem. There are many different conditions that cause sciatic nerve pain. There are common and less frequent causes of sciatica.
Common Causes of Sciatica
Injuries of the Low Back and Pelvis
Injuries can occur in many different ways. Some common examples of lumbar spine and pelvic injuries include: slips and falls, lifting heavy objects, crush injuries, car accidents, sports injuries, gardening, work related injuries, repetitive movements, and more. Injuries can cause herniated disc, strain muscles, low back muscle spasms, aggravated degenerative discs, facet syndrome, pinched low back nerves, sprained ligaments, exacerbate deformities in the lower back (i.e. spondlylolisthesis), and in more serious cases fractures of the lumbar spine, pelvis, or hip.
Low Back Disc Conditions
In between the vertebra of your lower back are located spongy shock absorbing disc that allow you better flexibility and protect the lumbar vertebra from fracturing by absorbing forces exerted on the lower back. Each disc is made up of annular ring fibers of cartilage that has a thick liquid nucleus. When the disc has pressure exerted on it, the thick liquid spread out causes the elastic cartilage fiber to flex and compress. If too much pressure is applied the disc the ring fibers of cartilage tear or crack. The leads to what many call a "slipped disc". However, the more appropriate name is herniated disc, protruding disc, or bulging disc. Whether the disc is herniated, protruding, or bulging these conditions often cause nerve root compression causing sciatica.
About the age of 25 years, the intervertebral disc begin to dehydrate, crack, and tear. Overuse and abuse to the lower back cause the once supple and elastic cartilage to become dry and hard like old shoe leather. Disc are like bags of fluid. When the disc is damage it begins the process of losing water or dehydrating. The dehydration process allow for the vertebra above to compress on the vertebra below causing a pinching of the spinal nerve root. With the degenerative process come inflammation of the joint, arthritis, causing the bones of the spine to grow bone spurs that can choke of the nerve holes and apply compression to the spinal nerves.
In the spine the spinal cord and spinal nerves descend through a hole in the vertebra called the spinal canal. As I mentioned earlier, that chronic inflammation of the disc and joints of the lumbosacral spine leads to arthritic bones spurs that choke of the spinal canal and also the nerve holes on the side called the neural foramen. Spinal stenosis is a progressive degenerative process that typically worsens as we get older.
Facets are the joints on the back of the vertebra. In the picture to the right you can see the arrow
pointing to the blue surface of the facets. That blue surface is really white in live tissue and is
rich in nerve endings. When vertebra are misaligned and the facets are jammed it results in
pinched nerves. This condition is called facet syndromes. Facet syndromes can cause sciatica.
Spondylolisthesis is a deformity of the lower back and many consider it to be a fracture because
the outer portion of bone in the vertebral region called the pars interarticularis is interrupted or
fractured. Now the vertebra that was one piece is now in two pieces. When you have a
spondylolisthesis the vertebral body moves forward. The greater the forward movement of the
vertebral body the greater the instability. Patients with spondylolisthesis have good days and bad
days both expected and unexpected. Spondylolisthesis occurs mostly in males and much less
common in females. Notice in the picture to the left, the arrow is pointing to the interruption of
pars interarticularis. Sciatica caused by spondylolisthesis respond well in a vast majority of
cases to chiropractic adjustments. Degenerative disc are also a byproduct of a spondylolisthesis.
The sacroiliac joint is where the wing bones of the pelvis (ilium) meets the triangular bone of the
pelvis(sacrum). When this joint is misaligned or out of place it causes pressure on the synovial
joint surface that is rich in nerve endings. When pressure is put on the joint surface it pinches
nerves that can cause sciatic nerve pain.
Less Common Causes of Sciatica
Fractures of the pelvis and lumbar spine can causes severe swelling or allow direct nerve
pressure from a fractured bone. Spinal cord or sciatic nerve tumors can also create a lot of
nerve pain. Pelvic infections or abscesses can cause a lot of swelling that will apply direct
pressure to the sciatic nerve. I have seen one case where severe kidney disease or renal failure
caused bilateral sciatic nerve pain. Pelvic disease or tumors also are a less common cause of