TENS is a noninvasive method for relieving pain. TENS units work by delivering small electrical impulses through electrodes that have adhesive pads to attach them to a person’s skin. These electrical impulses stimulate the body to produce natural pain relievers called endorphins. TENS units are also convenient because they are small, portable, and relatively discrete. People can carry a TENS unit in their pocket or clip it onto a belt to ensure that they have immediate access to pain relief throughout the day.