Doctors for Sciatica in Mulund: Expert Diagnosis, Advanced Treatment & Long-Term Sciatica Pain Relief Sciatica is more than just lower back pain—it is a condition caused by irritation or compression of the sciatic nerve, the longest nerve in the human body. The pain typically starts in the lower back and radiates through the buttock, thigh, and down the leg. It may also be accompanied by numbness, tingling, or muscle weakness, making everyday activities like walking, sitting, or standing extremely uncomfortable.