What is a TENS unit? What does it do?

TENS is the abbreviation for transcutaneous electrical nerve stimulation. TENS units are used to help control pain. They are usually small enough to fit in a pocket. They are issued by physical therapists and doctors when other pain management strategies aren’t working.


TENS units send small electrical currents through your skin, giving you a feeling sort of like a massage. The idea behind TENS units is that the electrical stimulation replaces the pain impulses. Doctors call this the gate theory. The gate theory suggests that when the electrical stimulation reaches the spinal cord first, the “gate” closes and blockes the pain impulses. As pain lessens, the muscles around the sore area relax, further lessening pain. TENS units can also be set to help your body release endorphins. Endorphins are body chemicals that reduce your feelings of pain.