What is TENS? Does TENS therapy work to cure pain?

For more than 50 years, transcutaneous electrical nerve stimulation (TENS) therapy has been used as a non-pharmacological way to manage pain. Traditionally, a TENS device was offered as a method of reducing pain while it was in use. But as musculoskeletal (MSK) care has advanced, so has our understanding of what TENS can and cannot deliver.

What is TENS?

TENS stands for transcutaneous electrical nerve stimulation (often written as T.E.N.S.) and involves non-invasive, wireless patches placed on the skin. These patches deliver mild electrical pulses to stimulate sensory nerve roots. By doing so, the therapy aims to reduce or “distract” pain signals as they travel to the brain. People often refer to the TENS device and accompanying treatment patches as a TENS unit or a TENS machine.

What is a TENS unit?

A TENS unit is a small, battery-powered device designed to deliver low-voltage electrical impulses through adhesive electrode pads placed on the skin. Often called a TENS machine, this device is used to provide temporary pain relief by stimulating the nerves near the area of discomfort and interfering with the way pain signals are sent to the brain. While TENS units can help mask pain during use and are widely available over-the-counter and in clinical settings, they do not treat or resolve the underlying issue that triggers the pain.

This type of tens nerve stimulation is designed to provide temporary pain relief, working while the device is active. Like opioids, TENS can mask pain symptoms rather. TENS units are not intended to repair injury or tackle the root cause of pain. Despite its widespread availability, TENS has significant limitations.

How does a TENS unit work?

The process is relatively simple:

• Small adhesive electrodes are placed on the skin near the area of discomfort.
• The device generates low-voltage electrical currents that pass through the skin.
• These impulses stimulate nerves in the targeted region.
• The goal is to temporarily block or alter the transmission of pain signals to the brain, creating a perceived reduction in pain.

While this mechanism may temporarily relieve discomfort, it does not heal or treat the p[ain or its cause. Unlike physical therapy, which focuses on restoring mobility and strength, TENS works only while the device is turned on.

Do TENS units help to cure pain?

TENS therapy aims to reduce pain while the device is in use. Neither chronic nor acute pain can be solved by intermittent periods of relief. TENS machines don't help to resolve or cure pain as they do not address the trigger or cause.

Clinical studies suggest that electrical stimulation may trigger the release of endorphins and interfere with pain signal transmission. This means some people experience short-term relief while using the device.

Commonly, TENS therapy has been tried for:

• Low back pain
• Neck pain
• Arthritis
• Post-surgical pain
• Labor-related pain

However, TENS units do not treat the root causes of chronic or acute pain. Relief disappears once the device is turned off, which limits its usefulness for MSK conditions and injury recovery.

Chronic pain and acute injuries cannot be resolved with short bursts of electrical stimulation. Because the therapy doesn’t address biomechanical dysfunction, inflammation, or behavioral factors that drive MSK pain, the underlying condition persists.

At Sword Health, we understand that solving pain requires habit-forming, guided movement, and the expertise of licensed physical therapists. That’s why TENS therapy is excluded from our care model.

Does Sword Health’s MSK programs use TENS?

At Sword Health, we focus on evidence-based treatment to deliver meaningful improvement, which means we rely on clinical results and science to deliver only the most appropriate and effective care for our patients.

We believe in a high-touch model of physical care, delivered by a team of licensed doctors of physical therapy. Their expertise, combined with sensor-based technology, is the best way to heal long-term. Because of our philosophy, we make the conscious choice to avoid TENS therapy in our approach.

High vs Low Frequency TENS

TENS therapy can be delivered at different frequencies, intensities, and pulse durations. Initially, devices used low-frequency stimulation. More recently, some MSK providers have experimented with high-frequency impulse therapy (HFIT), suggesting it may outperform low-frequency stimulation.

But here’s the problem: current evidence does not support this claim. While high-frequency implantable spinal cord stimulators have shown promising results, the same has not been validated for transcutaneous stimulation.

In fact, the only published study upon which solutions such as Enso have based their approach is exploratory. In this study, high-frequency stimulation was compared with no stimulation. Since the HFIT results in impulses that the member can feel (versus no stimulation), it is impossible to note placebo effects.

All studies around high versus low frequency TENS have focused solely on chronic low back pain, with no evidence on acute pain, or on pain affecting other areas of the body.

MSK solutions should be validating their care models against clinical-grade studies and results, and with the lack of clinical validation around TENS, Sword has chosen to avoid incorporation into our care model.

The problems and limitations of TENS vs physical therapy

Through the years, multiple efforts to conclude on the efficacy of TENS for acute or chronic pain have taken place, with over 160 systematic reviews and 50 meta-analyses conducted so far.

With all of this, the efficacy of TENS remains unclear. While many studies show positive effects, others state negative effects, and several systematic reviews conclude that there is insufficient evidence.

In relation to MSK conditions, TENS studies have focused on chronic low back pain and neck pain, but the question of its effectiveness still remains. There is currently no consensus on its clinical worthiness.

As a result, TENS is not suggested by clinical guidelines for the management of chronic low back pain (most importantly, the American College of Physicians / American Pain Society guidelines and the NICE guidelines). Additionally, the Centers for Medicare and Medicaid CMS issued a Medicare National Coverage Determination (NCD) in 2012 that allowed for coverage of TENS for chronic low back pain, only in the context of clinical trials. Since then, this coverage has expired, which has led several health plans to stop reimbursing for TENS therapy.

Most importantly, TENS does not address the underlying root causes of MSK pain, nor has it been proven to produce long-term relief. Evidence-based MSK care stresses that non-pharmacological approaches should be the mainstay treatment in MSK conditions. For solutions with the best outcomes, education, therapeutic exercise and behavioral change are driving care.

Can TENS be harmful?

While TENS is generally considered safe, risks and side effects exist:

• Skin irritation or rash at electrode sites
• Tingling or uncomfortable buzzing sensations
• Muscle spasms
• Increased tolerance (requiring stronger settings over time)

TENS is not recommended for people who are pregnant or have epilepsy, heart problems, or wear a pacemaker or other metal implants. Much like opioids, you can develop tolerance to TENS, rendering it ineffective when frequently used.

The most clinically-validated solution on the market

Musculoskeletal conditions are the leading cause of disability in the U.S. and one of the most expensive healthcare burdens. Evidence consistently shows that sustainable recovery comes from:

• Therapeutic exercise guided by experts
• Education that empowers individuals
• Behavioral change that supports long-term health

Sword Health’s Digital Physical Therapy programs deliver all three. We offer the most clinically-effective digital solution for MSK disorders with high-quality, personalizaed physical therapy plans delivered by licensed doctors of physical therapy combined with our FDA-listed devices and supporting AI technology.

Unlike TENS, Sword’s program is designed to address the physical and mental barriers to long-term pain relief.

FAQs

What does TENS stand for in therapy?TENS stands for transcutaneous electrical nerve stimulation.

How long does pain relief from TENS last?Relief typically lasts only while the device is on. Once removed, pain often returns.

Can TENS cure chronic pain?No. TENS may temporarily mask symptoms but does not address the underlying causes of pain.

Is TENS safe to use every day?While generally safe, frequent use can cause skin irritation and tolerance. It is not advised for everyone, especially those with pacemakers or epilepsy.

What are alternatives to TENS for MSK pain?Evidence-based care such as digital physical therapy, guided exercise, and behavioral support provide more sustainable outcomes.