‘Sciatica’ describes persistent pain felt along the sciatic nerve. This nerve runs from the lower back down through the buttock and into the lower leg. It is the longest nerve in the body. Pain results when this nerve is compressed or injured. It most commonly results from inflammation, bony enlargement due to arthritis, or a displaced (herniated) disk in the lower spine. Sciatic pain symptoms can be felt at any part of the nerve or along its entire length. Sciatica may take several forms, including: