The term “sciatica” refers to pain that is felt down the leg. The sciatic nerve is the large nerve that runs down the back of your leg. It is made up of several spinal nerves. Spinal surgeons tend to use the term radiculopathy or radicular pain rather than sciatica because it is usually a spinal nerve and not the sciatic nerve that is causing the pain.
Leg pain arising from the spine is usually due to spinal nerve compression and it is often felt going down the whole leg. Many patients with degenerative low back pain can experience leg pain, which is typically far less severe than the back pain, and it rarely goes below the knee. In contrast, patients with spinal nerve compression usually have far more leg pain than back pain.
Compression of a spinal nerve will usually cause symptoms of leg pain, numbness and tingling. Sometimes part of the leg can become weak and rarely bladder and bowel dysfunction can occur. The leg pain is usually severe and sharp. It is often described as burning in nature or like an electric shock.
Of course leg pain can have many different other causes. It can be classified into pain of spinal origin and non-spinal origin. For example, a disc herniation and spinal stenosis are spinal causes of leg pain, whereas osteoarthritis of the hip and knee are non-spinal causes of leg pain.