All About Electrotherapy and Pain Relief

If an individual is not experiencing sufficient control of pain and other symptoms, electrotherapy—a treatment that directs mild electrical pulses to the problem area—may be an option.

See Chronic Pain Coping Techniques – Pain Management

Electrotherapy includes a range of treatments using electricity to reduce pain, improve circulation, repair tissues, strengthen muscles, and promote bone growth, leading to improvements in physical functioning.

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Electrotherapy units usually consist of a battery-powered device connected by wires to adhesive electrode pads which are placed on the skin. The electrode pads are sticky, so they will adhere to the skin. Once the electrodes are attached and the unit is turned on, a mild electric current is sent to the skin via the electrode.

A number of newer electrotherapy devices bypass the wires, combining electrodes and battery power into a single unit that can be worn inconspicuously on the back, arm, leg, or elsewhere during work or other daily activities. A hand-held controller is used to adjust the level of stimulation.

While a large number of people find electrotherapy helpful, others do not. The medical literature on electrotherapy’s effectiveness has been mixed, and not all electrotherapy treatments are supported by research.

In This Article:

  • All About Electrotherapy and Pain Relief
  • How Electrotherapy Works to Ease Pain
  • Transcutaneous Electrical Nerve Stimulators (TENS)
  • Percutaneous Electrical Nerve Stimulation and Electrical Muscle Stimulation

Electrotherapy devices range in cost from less than $30 to hundreds of dollars. Several of the newer products are available over the counter, offering flexibility for those who can afford them. Devices sold without a prescription are often not covered by insurance, but people with health savings accounts may be able to apply funds from these accounts toward the cost. Trying electrotherapy in a medical or physical therapy setting before purchasing a unit may be helpful, since the therapy does not work for everyone. In some cases, a device can be returned if the treatment is not helpful, so saving the receipt is advised.

The Food and Drug Administration (FDA) verifies that these medical devices are safe to use, but does not test whether the devices are effective. Interestingly, the FDA process for approving a medical device is less rigorous than the approval process for drugs, which requires the pharmaceutical company to show evidence of a drug’s effectiveness before introducing it to the market.

When Electrotherapy Is Advised

Electrotherapy is typically used in conjunction with other treatments, rather than by itself. For people undergoing physical therapy, electrotherapy may alleviate pain sufficiently for an individual to participate more actively in targeted exercises. Electrotherapy is among pain relief options gaining attention as the potential risks and side effects of opioid (narcotic) medications have become more apparent.

See Opioid Medication Potential Risks and Complications

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Efforts to use electrical current to aid in healing go back to ancient times. The modern era of electrotherapy in the United States began with treatment for anxiety and depression, and the number of potential uses has grown since. Electrotherapy has been used to address chronic pain and chronic fatigue in general, as well as:

  • Diabetic nerve pain
  • Fibromyalgia
  • Migraine headaches
  • Wound healing
  • Stimulating bone growth

See Chronic Pain As a Disease: Why Does It Still Hurt?

Electrotherapy can take many forms, but the most common type is transcutaneous electrical nerve stimulation, or TENS.

While the concept of using electricity on the body may sound painful, many people find the sensation relaxing. With TENS, for example, the individual experiences a tingling, vibrating, or buzzing sensation.

The exact mechanism of electrical stimulation’s beneficial effect remains controversial. Electrical stimulation may directly block transmission of pain signals along nerves. In addition, electrical stimulation has been shown to promote the release of endorphins, the natural painkillers produced by the body.

See Therapeutic Nerve Blocks for Neuropathy

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Electrotherapy Side Effects

The most common side effect with electrotherapy is skin irritation or rash, caused by the adhesives in the electrodes or the tape holding the electrodes in place. Overusing electrotherapy may cause a burning feeling in the skin. Directions about the duration of therapy should be followed closely to avoid a problem.

Electrical stimulation should not be applied over malignancies or areas with broken skin or an infection. Bruising, bleeding, or infections are possible with the types of electrotherapy that penetrate the skin.

Placing the pads over the heart or over pacemaker leads could cause cardiac arrhythmia and placing them over a pregnant woman’s abdomen could cause fetal damage. In fact, people with pacemakers and pregnant women are generally advised to avoid electrotherapy altogether.

See Management of Back Pain in Pregnancy

Placing the pads over the throat could cause low blood pressure. Using electrotherapy while driving is not recommended.

In This Article:

  • All About Electrotherapy and Pain Relief
  • How Electrotherapy Works to Ease Pain
  • Transcutaneous Electrical Nerve Stimulators (TENS)
  • Percutaneous Electrical Nerve Stimulation and Electrical Muscle Stimulation
  • Other Electrotherapy Treatments

Types of Electrotherapy

All electrotherapy devices have certain similarities, such as using battery power to apply current to electrodes. The therapies vary in frequencies, waveforms, and effects, however. These are some of the most commonly used kinds of electrotherapy:

  • Transcutaneous electrical nerve stimulation (TENS)
  • Percutaneous electrical nerve stimulation (PENS)
  • Electrical muscle stimulation (EMS)
  • Interferential current (IFC)
  • Pulsed electromagnetic field therapy (PEMF)
  • Galvanic stimulation (GS)
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Ultrasound and laser therapy are often grouped with electrotherapy, or the wider category of electro-physical agents, despite not delivering an electric current. With ultrasound, sound waves are directed to the affected area to speed up the healing process. Laser therapy may also be used to help tissue heal, and provides a more targeted and intense treatment.

Transcutaneous Electrical Nerve Stimulators (TENS)

The most widely used type of electrotherapy is transcutaneous electrical nerve stimulation, or TENS.

What to Expect with TENS Therapy

TENS therapy typically uses electrodes on small, sticky pads attached via wires to a battery-operated device. The electrodes are placed over the area in pain, and current is sent through the electrodes, stimulating the sensory nerves and creating a tingling sensation that reduces the feeling of pain.

A hand-held controller allows the individual to select from a range of options, such as high frequency or low frequency current as well as complex patterns of stimulation.

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People are often introduced to TENS therapy during physical therapy or in a chiropractor’s office. This gives the individual the opportunity to see whether pain relief is sufficient to consider purchasing a TENS unit for home use.

See Chiropractic Services Beyond Adjustments

In recent years, a number of TENS products have been marketed as wearable devices. Some of these devices deliver current directly from electrodes in a battery-powered unit worn on the body. The unit may be strapped to a leg or attached to the back, shoulder, knee, or other part of the body. These devices are typically not visible under clothing.

Therapy may be done in 30-minute segments or run continuously. Overnight therapy is possible in some cases.

The response to TENS varies widely. While many individuals consider TENS a key part of their treatment, TENS does not relieve pain for everyone.

In This Article:

  • All About Electrotherapy and Pain Relief
  • How Electrotherapy Works to Ease Pain
  • Transcutaneous Electrical Nerve Stimulators (TENS)
  • Percutaneous Electrical Nerve Stimulation and Electrical Muscle Stimulation
  • Other Electrotherapy Treatments

Conditions Treated with TENS

Conditions responding well to TENS include, but are not limited to:

    • Neck pain and stiffness. Pain was reduced in severity over the short term in a study of people treated at several clinics who were provided TENS therapy.1

See Chronic Neck Pain: What Condition Is Causing My Neck Pain?

    • Low back pain is often treated with TENS, but the research has been conflicting.2,3

See Lower Back Pain Symptoms, Diagnosis, and Treatment

    • Diabetic nerve pain was reduced significantly for people who had TENS therapy in three medical studies analyzed. The effect lasted six weeks after the studies, but did not continue at the 12-week follow-up.4

See All About Neuropathy And Chronic Back Pain

    • Fibromyalgia pain. Tolerance during physical activity significantly improved for patients after a single TENS treatment in one research study.5

See Fibromyalgia Symptoms

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TENS is typically applied at the site of the pain, but is sometimes effective when used in other areas as well. Experimenting with various electrode placements and using a TENS unit for several days is recommended before buying a unit. Attaching electrodes in the area surrounding the site of the pain, over the nerve supplying the area in pain, or even on the opposite side of the body, may be useful.


  1. Escortell-mayor E, Riesgo-fuertes R, Garrido-elustondo S, et al. Primary care randomized clinical trial: manual therapy effectiveness in comparison with TENS in patients with neck pain. Man Ther. 2011;16(1):66-73.
  2. Johnson M, Martinson M. Efficacy of electrical nerve stimulation for chronic musculoskeletal pain: a meta-analysis of randomized controlled trials. Pain. 2007;130:157-165.
  3. Kroeling P, Gross A, Graham N, et al. Electrotherapy for neck pain. Cochrane Database Syst Rev. 2013;(8):CD004251.

Percutaneous Electrical Nerve Stimulation and Electrical Muscle Stimulation

Percutaneous electrical nerve stimulation and electrical muscle stimulation are two therapies that may be recommended if transcutaneous electrical nerve stimulation (TENS) has not been successful.

Percutaneous Electrical Nerve Stimulation Goes Deeper

Percutaneous electrical nerve stimulation refers to applying electrical stimulation through small needles which penetrate the skin.

As with TENS, small wires are attached to a battery-powered electrical stimulator. A key difference is that needle electrodes deliver current closer to the nerves or the muscles beneath the skin, making the nerves less sensitive to pain. PENS therapy is likely to be used first in a health care or physical therapy setting, but can also be used at home.

See Physical Therapy Benefits For Back Pain

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While some people see an improvement right away, multiple treatments may be required. Treatments typically last about half an hour. An easing of muscle spasms from PENS may allow greater range of movement, leading to better physical functioning overall.

Watch: Video: What Is Your Back Muscle Spasm Telling You?

There is considerable variation in the duration of pain relief from PENS. The therapy is long-lasting for many individuals, but others need repeated visits.

Diabetic peripheral neuropathy is one of the conditions in which PENS is often advised.6

Watch: Causes of Neuropathic Pain Video

In This Article:

  • All About Electrotherapy and Pain Relief
  • How Electrotherapy Works to Ease Pain
  • Transcutaneous Electrical Nerve Stimulators (TENS)
  • Percutaneous Electrical Nerve Stimulation and Electrical Muscle Stimulation
  • Other Electrotherapy Treatments

Electrical Muscle Stimulation Builds Strength

Rebuilding muscle tissue is the goal of electrical muscle stimulation, or EMS.

See Back Muscles and Low Back Pain

An electrical muscle stimulator appears similar to a typical TENS unit, with electrodes attached by wires to the small, battery-powered stimulator. In EMS, the current is directed at weakened muscles, rather than nerves, prompting the muscles to contract and gradually regain their strength.

EMS can be helpful for rehabilitation after muscles have been weakened substantially or for less serious conditions, such as a pulled muscle.

See Pulled Back Muscle and Lower Back Strain

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One medical research study looked at EMS to treat muscle atrophy after surgery to reconstruct an anterior crucial ligament. Half the participants were given EMS therapy, with a control group not receiving the therapy. Those using EMS had thicker muscles and better recovery of knee extension strength three months after the surgery.7

While EMS may be helpful in gradually strengthening muscle, people considering EMS are advised to be wary of exaggerated marketing claims that EMS is a quick fix for boosting muscle strength.


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