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The sciatic nerve is the largest nerve in the body, formed by nerve roots coming out of the spinal cord in the lower back. The nerve goes down through the buttock, then its branches extend down the back of the leg to the ankle and foot.
A herniated disc may
compress one or more of the nerve roots that form the sciatic nerve. Pressure
on one of these nerve roots will often produce distinctive symptoms of
sciatica, such as pain, numbness, weakness, and tingling
in the affected leg.
Although a herniated disc is the most common
cause of sciatica, sciatica can also be a symptom of other problems, such as
narrowing of the spinal canal (spinal stenosis), nerve root compression
resulting from injury, and certain rare tumors.
ByHealthwise Staff Primary Medical ReviewerWilliam H. Blahd, Jr., MD, FACEP - Emergency Medicine Specialist Medical ReviewerRobert B. Keller, MD - Orthopedics