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Sciatica

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Sciatica

Back Pain Slideshow

Medical Author: William C. Shiel Jr., MD, FACP, FACR
Medical Editors: Kenneth Kaye, MD, and Melissa Conrad Stöppler, MD

What is sciatica?

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.

What are symptoms of sciatica?

Sciatica causes pain, a burning sensation, numbness, or tingling radiating from the lower back and upper buttock down the back of the thigh to the back of the leg. Severe sciatica can make walking difficult if not impossible. Sometimes the symptoms of sciatica are aggravated by walking or bending at the waist and relieved by lying down.

How is sciatica diagnosed?

Sciatica is diagnosed with a physical exam and medical history. The typical symptoms and certain examination maneuvers help the health-care practitioner to diagnose sciatica. Sometimes, X-rays, films, and other tests, such as CT scan, MRI scan, and electromyogram, are used to further define the exact causes of sciatica.

Next: How is sciatica treated? »