Sciatica is symptomatic pain caused by compression of the nerve roots in the lumbar spine or sacral region. Compression of the sciatic nerve itself can cause sciatica. Normally associated with a slipped or herniated disc, sciatica may also be caused by compression of the peripheral sections of the sciatic nerve. In late pregnancy the uterus presses the sciatic nerve and this may also lead to sciatica.

Sciatica can be extremely painful and may restrict normal work schedule if it is severe. The pain is mostly episodic but can attain chronic proportions, if not attended to in time. As sciatica is a symptom and not a disease, understanding the underlying cause of the pain is imperative for any kind of sciatic nerve treatment.

A sudden twisting motion or an injury can cause a herniated disc. The soft inner core of the disc bulges out of the fibrous outer core and pressurizes the sciatic nerve causing sciatica. This is commonly referred to as a pinched nerve or a slipped or ruptured disc.

In adults over 60 years, the spinal canal narrows due to the natural ageing process. This condition is known as lumbar spinal stenosis and results from enlarged facet joints and the overgrowth of soft tissue. The resultant bulge causes the nerve to be compressed, which causes the pain.

Degenerative disc disease is a process and not a disease. A weakened disc leads to the inflammatory proteins getting exposed from the inside and these can also irritate the sciatic nerve.

Vertebrae, mostly in the lower back, get misaligned and slip over another. This leads to a condition known as spondylolisthesis and the misaligned vertebrae pressurizes the sciatic nerve.

Chronic breakdown of cartilage in the joints is the most common form of arthritis that usually occurs after middle age. This may cause bits of cartilage to float inside the spinal joints. When this occurs in the lower back region it can cause irritation and inflammation and this in turn can compress the sciatic nerve.

Though commonly associated with a compression of the sciatic nerve roots in the lumbar region, symptoms that are similar to sciatica (known as pseudo sciatica) can be caused by numerous other conditions too.

* Exertion or increased sports activity.
* Trauma.
* Unhealthy postures.
* Obesity.
* Diabetic Neuropathy.
* Alcoholism.

Besides a herniated disc, the other main cause of sciatica is poor postures due to habit or occupational compulsions like peering over the screen while working at a computer. Sitting or standing in a typical posture for longer periods too can activate a trigger point on the peripheral sections of the sciatic nerve.

Treating sciatica is of great importance due to its developmental nature. A painkiller can provide relief but it is, at its best, only a temporary treatment. Almost all long term treatments involve sciatica alternative remedies like exercises, yogic postures and postural aids.

References:

http://en.wikipedia.org/wiki/Sciatica

http://www.spine-health.com/topics/cd/d_sciatica/sc02.html

http://www.wrongdiagnosis.com/s/sciatica/underly.htm

http://www.bigbackpain.com/sciatica.html

http://www.medicinenet.com/sciatica/article.htm

http://spineuniverse.com/displayarticle.php/sciatica-causes-3101.html