The Science Behind TENS 👉 A TENS unit sends low-voltage electrical impulses through electrodes placed on the skin. These impulses interact with your nervous system and pain pathways in a few key ways: 🧠 1. Pain Gate Control Theory Your body has “gates” in the spinal cord that regulate pain signals traveling to the brain. When a TENS unit stimulates the nerves, it activates faster sensory nerve fibers (like those for touch and pressure). These fast signals can “close the gate” to slower pain si