A TENS unit, or Transcutaneous Electrical Nerve Stimulation unit, is a small device used to relieve pain. It works by sending low-voltage electrical currents through the skin via electrodes. This stimulation can help block pain signals from reaching the brain and may also promote the release of endorphins, the body's natural painkillers. TENS units are often used for various types of pain, including chronic pain, muscle soreness, and post-surgery discomfort. They are portable and can be used at home or on the go, making them a convenient option for many individuals seeking non-invasive pain relief.