The difference between transcutaneous electrical nerve stimulators, or TENS machines, and other electrotherapy and electrical stimulation (e-stim) devices, such as pulsed electromagnetic field (PEMF) devices, is often unclear.

Although there are some similarities, the ways in which each is applied, how this affects the body, and how they interact with the body are among the most significant differences between both devices.

PEMF devices use PEMFs and TENS units use electric currents. PEMFs affect your body cells and the brain in addition to boosting nerve activity. This means that in addition to the pain relief effects that TENS units have, PEMFs also promote deeper healing.

TENS devices are used to aid patients in pain management. They operate using a distraction strategy known as the gate control theory. TENS basically works by competing with signals from another pain source to confuse the brain through stimulation signals that are produced.

For example, TENS is comparable to stamping on your big toe when you have a headache. The headache is now being overshadowed by the toe pain, which is worse. Typically, this is a fairly transient advantage.

PEMFs are intended to promote tissue healing at the cellular level, even though they also frequently provide more effective, long-lasting pain relief. Long-lasting pain alleviation results from the repair and mending of the pain’s underlying causes.

 TENS is therefore primarily used to treat pain, usually without addressing the underlying cause of the pain. PEMFs have a wide range of other medical uses in addition to relieving pain.

Research has shown that PEMFs can boost healing of wounds and repairing of bone fractures, have a favorable effect on depression and anxiety, and enhance sleep quality and have many more benefits beyond pain alleviation.

TENS stimulates neurons and activates the opioid system, and PEMFs repair cells and tissues at the mitochondrial level, altering how pain is perceived. TENS devices just treat the pain associated with the injury; they have no effect on actual healing.

Whereas PEMFs can reduce pain and heal many more problems. Additionally, PEMF therapy is very successful at repairing damaged cells, stimulating neurons, reducing inflammation, and promoting the growth of new cells.

There are many benefits to choosing PEMF therapy over TENS therapy, including the ability of a PEMF device to alleviate pain.

Beyond the therapeutic advantages that they really provide, convenience is another aspect that makes PEMFs a more desirable choice.

TENS units are more challenging to use because they require direct skin contact. PEMF devices, on the other hand, can be worn over light clothing and used while doing other activities, such as while driving or simply sitting in your chair in a cubicle.

PEMF devices can target more surface of the body at once than TENS units can because they have various unique delivery options, such as a chair pad, total body pad, or smaller rings and paddles. Electrodes have to be transferred from one location on the body to another while using a TENS unit, which can require extra time and effort.

How does TENS work?

TENS is an electrical stimulation which primarily aims to provide a degree of symptomatic pain relief by exciting sensory nerves and thereby stimulating either the pain gate mechanism and/or the opioid system.

The different methods of using TENS relate to these different physiological mechanisms. The effectiveness of TENS varies with the clinical pain being treated; however, research would suggest that when used “well,” it provides significantly greater pain relief than a placebo intervention.

There is a vast research basis for TENS in both the clinical and laboratory settings, and while this summary does not provide a thorough review of the literature, the important studies are mentioned.

It is worth mentioning that the word TENS could describe the application of any electrical stimulation using skin surface electrodes which activate nerves.

In the clinical context, it is most commonly assumed to refer to the use of electrical stimulation with the specific intention of providing symptomatic pain relief.

If you do a literature search on TENS, do not be surprised if you come across a whole lot of “other” types of stimulation which technically fall into this grouping.

The TENS unit tries to stimulate (excite) the sensory nerves and thus activate particular natural pain-relieving mechanisms.

For simplicity, one can assume that there are two basic pain relief mechanisms which can be triggered: the pain gate mechanism and the endogenous opioid system; the variation in stimulation settings needed to activate these two systems will be briefly reviewed.

Pain relief by means of the pain gate mechanism involves activation (excitation) of the A beta (Aβ) sensory fibers, thus reducing the transmission of the noxious stimulus from the ‘c’ fibers through the spinal cord and on to the higher centers.

It seems that the A fibers enjoy being stimulated at a high frequency (90-130 Hz or pulse per second). It is difficult to find support for the concept that there is a single frequency that works best for every patient, but this range appears to cover the majority of individuals.

Clinically, it is important to enable the patient to find their optimal treatment frequency, which will certainly vary between individuals. Setting the machine and telling the patient that this is the “right” setting is certainly not going to be the maximally effective treatment, though of course some pain relief may well be achieved.

An alternative strategy is to activate the endogenous opiate (encephalin) in the spinal cord, which will reduce the activation of the noxious sensory pathways by stimulating the A delta (A) fibers, which respond preferentially to a much lower frequency (2-5 Hz).

This will activate the opioid mechanisms and provide pain relief. Patients should be encouraged to explore their alternatives whenever feasible as, similar to the pain gate physiology, it is doubtful that there is a single (magic) frequency in this range that works the best for everyone.

Another option is to use burst mode stimulation to activate both types of nerves simultaneously. In this case, the higher frequency stimulation output is interrupted (or burst) at a rate of roughly 2-3 bursts per second.

The higher frequency stimulation output is normally at about 100 Hz. When the machine is turned on, it will send out pulses at a rate of 100 Hz, activating the A fibers and the pain gate mechanism.

However, because of the pace of the burst, each burst will cause excitement in the A fibers, triggering the opioid processes. This method of pain relief is by far the most effective for some patients, but many patients find it less comfortable than some other types of TENS because it causes more muscle twitching and more of a “grabbing” or “clawing” sensation than the high- or low-frequency modes.

When opposed to pharmacological therapy, TENS is a noninvasive treatment method with low adverse effects. The most frequent complaint (affecting 2%-3% of patients) is an allergic-type skin reaction, which is almost invariably caused by the electrodes’ substance, the conductive gel used to hold them in place, or the tape used to secure them.

Most TENS applications are now made using self-adhesive, pregelled electrodes which have various advantages including reduced cross infection risk, ease of application, lower allergy incidence rates, and less expensive.

Although there is currently little clinical evidence for increased efficacy, digital TENS machines are becoming more commonly available and adding more capabilities (such as automated frequency sweeps and more sophisticated stimulation patterns). Some of these gadgets do provide therapy settings that are preprogrammed and/or automated.

How does PEMF work?


Three categories of PEMF action mechanisms—physical mechanisms, biophysical mechanisms, and solely biological processes—can be distinguished.

While the physical mechanism of action is relatively simple, well known, and related to Faraday’s law of induction, which states how “a time-varying (pulsating) electromagnetic field induces an electric field in a nearby conductor,” the mechanisms of action of biophysical and biological processes are indeed very complex.

The target tissue is struck by an electromagnetic field with each and every pulse. The plasma membrane of cells experiences a brief depolarization as a result of this stimulation, which is its primary effect.

This event produces highly important secondary effects (a biophysical process) by the brief opening of certain transmembrane ion channels, among which the voltage-dependent channels for the calcium ion (Ca2+) stand out.

In reality, calcium is a crucial second cellular messenger because it enters the cell and binds to calmodulin at the cytoplasmic level within milliseconds of a single pulse, causing various metabolic pathways to cascade in the cytoplasm.

Nitric oxide is released, in a matter of seconds from a single pulse, by the activation of the cytoplasmic nitric oxide synthase, among other enzymatic activations.

Nitric oxide, a soluble hormone, in turn, stimulates a complete set of metabolic pathways, one of which leads to the formation of cyclic guanosine monophosphate, another second messenger, in a time equal to seconds/minutes from a single pulse.

From this point, the biological tertiary effects of PEMFs start to show effect. These effects last from a few hours to days and weeks after the initial impulse and include the transcriptional activation of numerous genes into the cell nucleus with the production of growth factors and other proteins and transmembrane receptors that will cause the orientation of the cells to regeneration and resuscitation regardless of the tissue they are a part of.

Macroscopically, we can see the elimination of swelling, discomfort, and inflammation and whole tissue regeneration, including neovascularization and extracellular matrix remodeling until the total repair of the wounded tissue.

All the cells involved in an injury respond to the action of PEMF, including endothelial cells (which will rebuild the injured blood vessels), fibroblasts (which will proliferate and repair the injured extracellular matrix), muscle cells, chondrocytes, and osteoblasts (which will undergo a more rapid and efficient proliferation).

Instead, the immune system cells, particularly the inflammatory component, are calmed (interleukin levels are lowered), and the activation of monocytes to macrophages is preferred to get rid of the damaged area of bacteria, foreign objects, and dead cells.

In the end, PEMF limits the potential of acute inflammation—necrosis and chronic inflammation—and supports the regeneration of cells and tissues.

Additional applications of PEMF that make it superior to TENS

PEMF, as previously noted, stimulates tissue healing and is used in various disciplines of medicine to improve healing following various types of traumas, injuries, postsurgical wounds, and inflammations.

 Bone fractures, arthritis, osteoarthritis, acute and chronic inflammation, edema, discomfort, chronic pain, wounds, and chronic wounds are among the pathologies for which this technique can be used effectively.

PEMFs are also used in sports medicine, fitness, physiotherapy, orthopedics, osteopathy, rehabilitation, and orthopedics, including the neuromuscular recovery of post-workout athletes.

Along with those already mentioned, the pathologies and disorders that may be included cover all wounds, traumas, and inflammations affecting the shoulder, elbow, hand, knee, spine, hip joint, ankle joint, and foot.

All arthritic pains, pain at the point where tendons insert (such as in tennis arm, golfer’s elbow, pitcher’s shoulder, and scapulohumeral periarthritis), overload syndrome, patellar pathology, meniscal pathology, degeneration of the intervertebral discs and vertebral joints, “witch stroke,” cervical spine pain from “whiplash,” ischial pain, muscle contractures, and posttraumatic results may also be included.

 Flat foot discomfort, bursitis, inflammation of the Achilles tendon, all degenerative symptoms, painful tendon insertions, and calcaneal spine pain may also be treated using PEMFs.

Recent studies also consider their use as an adjuvant therapy for complex illnesses like tumors, microbial infections, neurological disorders, cardiovascular diseases, and diabetes. There are no known side effects of PEMFs.

1.Wound recovery

PEMF has historically been used mostly for the treatment of wounds. A complex series of inflammatory, proliferative, immunological, and tissue remodeling processes takes place during the healing of a wound.

According to clinical research, PEMF therapy can help and speed up the healing of both recent and new wounds, including postoperative wounds and chronic wounds such as pressure sores and diabetic leg and foot ulcers.

The increased vascularization caused by PEMF stimulation in the tissue, along with greater oxygenation and perfusion of the wounded tissue, all appear to play a role in the underlying mechanism this ability of healing wounds.

By encouraging endothelial cells to divide and repair damaged blood vessels, PEMF gradually increases angiogenesis in the tissues that have been damaged by the wound.

Additionally, PEMF induces fibroblasts to repair the damaged extracellular matrix and epithelial cells to procreate and causes tissue continuity to be lost.

The fact that PEMF stimulation synchronizes the reproduction activity of the cells exposed to the electromagnetic field so that no cell species can favor one over another is a crucial and really intriguing feature.

While research on this specific process is ongoing, its effects are already apparent in the way that PEMF treatments promote the first or a closely related first goal rather than the second purpose in the healing of fresh wounds.

This indicates a reduction in the growth of keloids and unsightly scars. Additionally, PEMFs relieve pain and inflammation right away. This is important for managing all wounds, but postoperative wounds in particular.

2.Bone remodeling and healing

Osteoblasts and osteoclasts, two distinct bone cell types, must work together for bone healing. PEMFs stimulate fibrocartilage calcification in the space between bone segments, increase blood flow and wound healing by stimulating calcium ion channels, and increase the bone formation rate by osteoblasts which are a few mechanisms of PEMFs in bone repair.

 Instead, it is discovered that osteoclastic activity is decreased. In addition, PEMF has shown to be a very successful treatment for unconsolidated fractures.

3.Osteoarthritis, arthritis, and osteoarthritis treatment

Osteoarthritis and rheumatoid arthritis, as well as other types of arthritis, have been successfully treated using PEMF stimulation. PEMF is an adjuvant in the management and treatment of pain because it reduces the inflammatory response.

4.Management of tendinitis

Even in patients with the disease who do not respond to or are unable to receive corticosteroid-based medication therapy, PEMF can reduce discomfort and promote mobility starting from the first applications.

5.Cancer adjuvant treatment

Studies that are relatively new explore the potential use of PEMF as an adjuvant in the nonsurgical management of tumor pathologies, particularly solid tumors. In vitro and in vivo studies, as well as clinical case studies, are conducted on animal models.

The initial findings are quite promising because they show that tumor angiogenesis, cancer cell growth rates, and cancer cell viability are all reduced or delayed.

Additionally, PEMF encourages the apoptosis and/or necrosis of tumor cells. The underlying biochemical mechanisms of what is observed are not yet fully understood, but it is assumed that PEMF, while inducing homeostasis in a normal cell, reactivates metabolic and signaling pathways bypassed or silenced by the neoplastic transformation process in a tumor cell, leading the cell to undergo apoptosis or necrosis.

In clinical settings, it has been observed that some frequencies (tumor-specific frequencies) affect cancer cells while others have no effect on metastases or tumor cells and only affect the healing of lesions.

This is especially true in the postsurgical period following the excision of a solid tumor, when wounds heal more quickly and effectively, recovery times are shortened, infections are avoided, and postsurgical scarring is avoided.

Despite the promising outcomes of the initial investigations, the use of PEMF in the field of oncology is still being studied and needs more research. Read more on PEMF Therapy for cancer.

6.Management of insomnia

The research has revealed one benefit of PEMF therapy that you might not have anticipated. PEMF therapy works well to cure various sleep problems, including insomnia. In just 4 weeks, 90% of participants in a double-blind study conducted in 2012 reported feeling relief from their insomnia and 75% reported no longer experiencing any sleeplessness at all.

This is a big advantage as sleep stimulates cellular regeneration, which is a crucial part of the healing process. It’s simple, efficient, and practical. Additionally, not only can sleep disorders be treated, but the underlying cause, which is typically depression, can also be healed. As a result, sleep problems might not recur in the future.

7.PEMF and weight loss

PEMF therapy can have a positive effect on areas such as fat reduction and weight loss. Because PEMF therapy directly stimulates cells, more energy is produced, which jumpstarts metabolism.

Additional ways that PEMF therapy can aid in weight loss include improved circulation and the release of fatty acids from fat cells. In the bloodstream, where they can be used as energy by the body, resistant fat deposits can be mobilized with improved circulation.

The brain’s reward regions and gut bacteria both have a significant effect on weight loss. PEMF therapy stimulates the reward centers, which decrease cravings. It also helps shift the bacterial balance to a more advantageous state, which promotes weight loss.

Enhanced value and safety of PEMF over TENS

In addition to all the additional advantages that PEMF therapy has over TENS therapy, which is only used to treat pain, PEMF devices have an unblemished safety record and are a much better investment because of various functions each unit can perform.

According to animal studies, stimulation frequencies above 20 Hz can have unfavorable side effects. TENS devices are frequently set at more than 50 Hz, limiting their use to occasional, short-term use of 30-60 minutes per day.

On the other hand, PEMFs are frequently set below 20 Hz—oftentimes, even below 10 Hz. If desired, this low frequency treatment can be administered repeatedly throughout the day for lengthy periods of time. Some systems can even be left running all night, aiding in restful sleep and healing without interfering with your day.

Unlike many conventional treatments for pain and other disorders, properly applied PEMFs have not been associated with any negative side effects. As opposed to painkillers, PEMFs always flow through the body; therefore, there is no risk of an overdose.

A TENS unit has extremely specific uses; therefore, your investment can end up on the shelf more frequently than it is actually used.

But PEMFs have a wide range of medical applications and are also excellent for preventative care. So even after the condition has been cured for which you bought the device, investing in one can still benefit you (and your entire family) in various ways.

To learn more about PEMF therapy and its applications, please visit