Can you tell me about a device called TENS? Will it relieve my back pain?

Q. Can you tell me about a device called TENS? Will it relieve my back pain?

A. TENS stands for transcutaneous electric nerve stimulation. The device is intended to relieve pain by preventing pain signals from reaching your brain.

TENS is safe and painless, but it isn’t always effective.

With TENS, small electrodes are placed on your skin, generally near the area of your pain. The electrodes are attached to a small portable stimulator that you wear. The stimulator delivers tiny electrical impulses that pass through the electrodes to nearby nerve pathways. You turn the TENS unit on and off as needed to control pain.

Exactly how the impulses may relieve pain is uncertain. One theory is that they stimulate production of endorphins, your body’s natural pain killers.

TENS must be prescribed by a doctor. Often, a physical therapist working with the doctor will determine where the electrodes need to be placed and instruct you on how to use the device. The units can be rented or purchased.

TENS works best when used to relieve acute pain associated with a pinched nerve, such as sciatica. It’s less successful for chronic pain, although some people with chronic pain are occasionally helped by the device. Most often, TENS is used in conjunction with other pain-relief treatments, including exercise. People who have pacemakers usually aren’t candidates for TENS treatment.