The sciatic nerve is the the longest and thickest nerve in the human body, but it can quite easily be damaged.  The two sciatic nerves in our body begin on either side of the base of the spine and extend down through each of our legs.  These nerves have a long trajectory, but most of the time, the damage suffered by the sciatic nerve happens right at the root of the nerve, very near the spine.  This is a very sensitive area of the body, since the spine can suffer a number of traumas which affect the spinal column, and in some cases, also cause damage to one of the sciatic nerves which emanates from it.

Damage to the sciatic nerve is cause primarily by compressing this nerve and not allowing the blood to flow normally.  When the nerve is restricted or squeezed, this causes swelling and inflammation.  The resulting pain ranges from a mild numbness or tingling to severe spasms and cramps, and the inability to stand or walk.

The presence of a herniated lower spinal disk generally results in sciatica.  The bulging of the hernia pinches the sciatic nerve, cause sciatica pain.  Once the hernia is removed, the pain disappears.  If, however, the damage to the sciatic nerve is caused by bad posture or another back injuring activity, the pain will continue if the activity is not suspended.   Sciatic nerve pain will subside and the nerve will heal naturally over the space of several weeks, if no further damage occurs.