You get sciatica buy a spinal nerve's being irritated, once or over a period of time. You may develop sciatic leg pain due to many different conditions singly or in combination: stenosis, disc herniation, facet syndrome, etc. Sometimes the spinal nerve is mechanically irritated by a disc herniation, pressing into the spinal canal or chemically irritated by disc material that finds its way into the canal where it isn't supposed to be.
Sometimes you can recall a specific incident that caused your leg pain to begin, but more often, you can't point to one event. A lifetime of small events often accumulate to result in sciatica due to poor posture, too much heavy lifting, extra pounds of weight. These stresses build up to one day when a normal thing like bending to pick up the newspaper results in shooting pain to foot.
Contact Medical Spine and Sports Injury and Rehab Centers today for an evaluation of your sciatic leg pain, the first step toward its relief.