sciatic nerve

The sciatic nerve is the body's longest and largest nerve, running from your lower back through your hips and buttocks down each leg. It is made up of several nerve roots originating from the lower spine, which combine to form this single nerve. The sciatic nerve transmits signals that control muscles in the back of your thigh, leg, and foot, and carries sensory information from these areas to your brain. When it becomes irritated or compressed—due to conditions like herniated discs or muscle tightness—it can cause pain, numbness, or tingling that radiates from your lower back down the leg, commonly known as sciatica.