The sciatic nerve extends from your lower back to the back of your legs and is the longest nerve in your body. When it gets injured or compromised, pain can spread from your lower back to your hips, buttocks, and the back of either or both of your legs. Sciatica is an umbrella term for the collection of symptoms associated with sciatic nerve pain. Sciatica symptoms are usually felt on only one side of your body, but not always. The sciatica experience may vary by individual.