Sciatica is a nerve disorder, which affect the sciatic nerve. This nerve is a major nerve that starts at the base of the spine, runs down through the buttocks and the back of the leg into the foot. The condition most commonly occurs when this nerve is pressured due to injury of the prolapsed of a disk. Occasionally pressure may come from a tumor, blood clot or from sitting in an awkward position. Symptoms include pain, which shoots down the leg. There may be numbness and weakness in the affected area. Treatment begins by determining, if possible, the underlying cause. If the source of the pressure is found, treatment means removing that pressure. If the source is not found, treatment centers on reducing the pain.