Sciatica describes pain that follows the territory of the sciatic nerve. Typical is pain radiating from the buttock over the back of the thigh into the lower leg or foot, often accompanied by sensory disturbances or tingling.
Causes include a herniated disc in the lower lumbar spine, spinal canal stenosis, foraminal stenosis or irritation of the nerve by surrounding structures such as the piriformis muscle (piriformis syndrome). Diagnosis includes clinical tests such as the Lasègue sign and, where appropriate, imaging.