Sciatica refers to pain that radiates along the path of the sciatic nerve, which extends from the lower back through the hips, buttocks, and down each leg. This condition typically occurs when the sciatic nerve is compressed or irritated, often due to a herniated disc, bone spur on the spine, or narrowing of the spinal canal (spinal stenosis). Sciatica can cause varying degrees of pain, numbness, tingling, or weakness in the affected leg, making it difficult to sit, stand, or walk comfortably.