Sciatica is a name that is used for many discomforts in the lower back. The real cause of Sciatica is an irritation of the sciatic nerve. This nerve runs, with its branches, from the spine through the pelvis to the leg. If the nerve gets irritated somewhere from the spine before it enters the leg, it is officially called a Sciatica.
The symptoms manifest themselves often as pain in the buttock, radiating to the hip and often to the leg, to the calf and even into the foot. This all may be associated with or without back pain, while the cause is often located in low back.
There are basically three areas where the sciatic nerve might be trapped: in the spine, in the pelvis and the buttocks. In the spine, a vertebrae or an inflamed joint could give pressure to the roots of the sciatic nerve and cause radiation. An inflamed intervertebral disc could be the cause of this as well.