The diagnosis of ‘sciatica’ means that there is inflammation of the sciatic nerve. The sciatic nerve supplies information about movements to the leg, and sends information about sensations back to the brain. The sciatic nerve is quite large in fact, it is the largest peripheral nerve in the body.
The sciatic nerve is formed from the lower segments of the spinal cord; it is made up from the lumbar and sacral nerve roots from the spine. The sciatic nerve exits the lower part of the spinal cord (lumbosacral region), passes behind the hip joint, and runs down the back of the thigh.