Most cases of sciatica originate in the lower spine. A common cause is a bulging or herniated disc that presses against the sciatic nerve. Degenerative changes in the spine can also reduce space around the nerves, leading to irritation and pain. Lifestyle factors often play a role as well. Poor posture, prolonged sitting, lack of physical activity, and improper lifting techniques place additional stress on the lower back. Muscle tightness and spinal misalignment can further increase pressure on the sciatic nerve. Because sciatica may result from different causes, accurate assessment is essential for effective care.