Sciatica: Symptoms and Possible Causes

Is sciatica a spinal disorder or a symptom of a spinal disorder?

Written by Steven R. Garfin, MD
Reviewed by Richard D. Guyer, MD

The term sciatica is commonly used to describe pain traveling in the distribution of the sciatic nerve, so it's more accurate to say that it's a symptom of a spinal disorder not a spinal disorder itself. Common symptoms of sciatica include:

Where is the Sciatic Nerve?
Sciatic nerve fibers begin at the 4th and 5th lumbar vertebra (L4, L5) and the first few segments of the sacrum. The nerve passes through the sciatic foramen (a nerve passageway) just below the piriformis muscle (rotates the thigh laterally), to the back of the extension of the hip and to the lower part of the gluteus maximus (muscle in the buttock, helps with thigh extension).

The sciatic nerve then runs vertically downward into the back of the thigh, behind the knee and branches into the hamstring muscles (calf) and further downward to the feet.
Nerve Compression Can Cause Sciatica
Compression of the sciatic nerve can cause any of the above-cited symptoms. Rarely is nerve damage permanent, and paralysis is seldom a danger since the spinal cord ends before the first lumbar vertebra.

Certain lumbar (low back) spinal disorders can cause or contribute to sciatica symptoms, and include:

How Your Doctor Diagnoses Sciatica
Your doctor’s evaluation of your pain and other symptoms includes discussing your medical history, recent accidents or injuries (eg, falls), and a review of your current medications (both over-the-counter and prescription). He will perform a physical evaluation using one or more movement tests to help determine the source or causes of your pain. During the neurological part of the examination, your reflexes and muscle strength are tested. If necessary, he will order imaging studies, such as an x-ray, CT scan, or potentially an MRI. The imaging tests may help confirm your diagnosis.

Your doctor may ask you several questions, such as:

SpineUniverse Editorial Board Commentary

By Richard D. Guyer, MD

Dr. Garfin very nicely described the causes of sciatica and helped explain away the myths related to sciatica. However, not all buttock and leg pain is sciatica as there are many other structures in the spine that can cause these types of pain. For example, the sacroiliac joint (the joint between the pelvis and sacrum, the lowest segment of the spine) can cause or refer pain to the buttock and so can a sprain of the facet joints, which are the connecting joints in the back part of the spine.

Sometimes a tear of the disc can refer pain down into one's leg. If buttock and leg are associated with any neurologic symptoms of numbness or weakness it is "real sciatica" and needs to be evaluated by a spine care specialist. If severe neurologic symptoms occur along with bowel or bladder control problems, this is an emergency and needs to be evaluated as soon as possible.

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