Sciatica is pain resulting from irritation of the sciatic nerve. The pain of sciatica is typically felt from the low back to behind the thigh and radiating down below the knee. The sciatic nerve is the largest nerve in the body and begins from nerve roots in the lumbar spinal cord in the low back and extends through the buttock area to send nerve endings down the lower limb.

What are causes of sciatica? While sciatica is most commonly a result of a disc herniation directly pressing on the nerve, any cause of irritation or inflammation of this nerve can reproduce the symptoms of sciatica. These causes include irritation of the nerve from adjacent bone, tumors, muscle, internal bleeding, infections, injury, and other causes.