The term sciatica describes the symptoms of leg pain and possibly tingling, numbness or weakness that originates in the lower back and travels through the buttock and down the large sciatic nerve in the back of the leg.
While sciatica is most commonly a result of a lumbar disc herniation directly pressing on the nerve, any cause of irritation or inflammation of the sciatic nerve can reproduce the symptoms of sciatica. This irritation of nerves as a result of an abnormal intervertebral disc is referred to as radiculopathy. Aside from a pinched nerve from a disc, other causes of sciatica include irritation of the nerve from adjacent bone, tumors, muscle, internal bleeding, infections, injury, and other causes. Sometimes sciatica can occur because of irritation of the sciatic nerve during pregnancy.