How Does TENS Therapy Work?

TENS therapy

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TENS therapy is a pretty common treatment for any condition that causes muscle pain, like fibromyalgia. And if you spend any time reading about these kinds of conditions, or in a physical therapist’s office for therapy, you’ll probably end up considering it at one point or another. So if you’re curious about a TENS machine, you’ve come to the right place.

Let’s talk about what TENS therapy is, how it works, and if it’s really as effective as a lot of people claim it is.

What Is TENS Therapy?

TENS stands for “transcutaneous electric nerve stimulation.” And essentially, TENS therapy uses a small machine, usually battery powered and portable, that sends a small electric current through the skin and into the underlying muscle.

It’s a fairly common method of treating muscle pain and is frequently used by sports therapists to help athletes recover from injuries faster. And people with arthritis sometimes use it to deal with the joint pain of the condition.

Usually, a TENS unit has an adjustable knob that allows patients to slowly turn up the voltage. TENS machines typically aren’t powerful enough to be dangerous and are designed to simply offer mild stimulation of the nerves. This fact, along with the fact that it is portable, means that you can actually purchase your own TENS unit and carry it with you throughout the day, and use it only when you feel pain.

That’s good news because the relief that TENS offers tends to be short lived. So, someone using it for chronic pain would have to turn the machine on several times a day to get the best results.

How Does It Work?

The idea behind TENS therapy is that the electric signals disrupt the neural pathways what cause our brains to register pain. The nerves in your muscles transmit electrical signals to your brain when they are damaged, which in turn is interpreted by the brain. The brain then sends its own signals back to the muscle, which we then perceive as pain in that muscle.


People using TENS machines hope that by sending an external electric current into that nerve connection, it will overwhelm the pain signals, which disrupts your bodies ability to process pain. In addition, many proponents of the therapy argue that the electric current stimulates the body’s natural healing process, leading to faster recovery times.

And finally, some theorize that TENS therapy triggers the endorphin system. Endorphins are a chemical released in the body that stimulates pleasure centers in the brain and dulls the sensation of pain. The idea is that it releases these endorphins and thus leaves you feeling better.

But the scientific basis behind the therapy is actually a little bit spotty.

Is It Effective?

There’s no question that some people who use TENS therapy report a decrease in their pain symptoms. There are numerous studies that back up the idea that TENS seems to work for some people.

But in many of these studies, the effectiveness of the therapy seems to vary widely. Some people report positive results while people with the same condition, at the same voltage, don’t see any improvement at all. It could be that some people are simply more likely to respond positively to it based on genetic makeup or body composition or any number of other factors. That could explain why results seem so variable.

But some have argued that these mixed results are better explained by something called the sensation-enhanced placebo effect. You see, the placebo effect is a well-understood principle in medical research where people who have been given an ineffective treatment seem to feel better anyway. They believe that the treatment was effective and so they report an improvement in symptoms.

The sensation-enhanced placebo effect is essentially the same thing but with a tool like a TENS unit that causes a physical sensation in the subject. So not only does someone using it believe they are receiving an effective treatment, but they feel like the machine is clearly doing something because they can feel the electric pulse.

This would explain why some people report success with TENS but others don’t. Some people are more susceptible to the placebo effect than others. But with that being said, anything that leaves you feeling better is a valid form of treatment. What matters when it comes to treating chronic pain are results that make it easier for you to live a normal life. So if you think a TENS unit may help you, there’s little harm in trying. Just don’t expect wonders from it.

So let us know, do you use TENS therapy for pain? Does it work for you? Tell us in the comments.