What is a TENS Unit? + How to Use & How Does it Work

Tens Machine

What is a TENS Unit? + How to Use & How Does it Work

A TENS machine is an electronic medical device. TENS is an abbreviation of Transcutaneous Electrical Nerve Stimulation.

Transcutaneous means “across the skin”. In simple terms, a tens machine stimulates your nerves via an electrical current through your skin.

What Does a TENS Machine Do?

A TENS machine may assist you in modest short-term pain relief.

The use of a TENS machine should be as one part of a pain management program under the guidance of your doctor or healthcare practitioner. Your health practitioner should always be consulted before using a TENS machine.

How Could a TENS Unit Decrease Pain?

Pain is thought to be controlled by TENS in one of two ways:

Sensory Level Stimulation – The Gate Control theory of pain means that the electrical input of the TENS machine interferes with the transmission of pain signals, by blocking the neural “gate” through which the pain travels.

Motor Level Stimulation – The goal of motor level stimulation is to cause the release of the body’s own opiate- substances to achieve pain relief.

How Do You Use Use a TENS Machine for Pain Relief?

If we use back pain as an example, you can use a TENS machine by placing the TENS machine electrodes either side of your spine at the same level as your back.

If you have a 2-channel TENS machine you can also place the second set TENS electrodes either side of your spine at a level above your pain eg between your pain and your brain.

Please note that you should not place your TENS electrodes on your skull (brain), the front of your neck, or through your heart.

For professional advice regarding your TENS electrode placements and dosage, please consult your physiotherapist.

More examples of TENS Machine electrode placements can be found here:

  • Tens Machine Electrode Placements? (eBook)


Use only as directed. A TENS machine and EMS machine are electronic medical devices.  Always read the label and instruction manual. A TENS machine may assist you in modest short-term pain relief. Consult your doctor/healthcare professional prior to use and if symptoms persist. 

What is a TENS machine?

What is an EMS machine?

Buy TENS machine electrodes and replacement electrode leads.

TENS Machine FAQs

  • What is Pain?
  • What is EMS (Electric Muscle Stimulation)?
  • How to Use a TENS Machine
  • TENS Machine – Private Health Insurance Rebate
  • What is a TENS Machine?
  • What is Nerve Pain?
  • Tens Electrode Placement Tips

    Where to Position Your TENS Machine Electrodes?

    For specific advice on TENS machine electrode placements and TENS machine settings, you are advised to seek the professional assistance of a health professional with expertise in the use of TENS machines such as your physiotherapist. 

    Where NOT to Use Your TENS Machine

    TENS machine or EMS electrodes should NEVER be placed:

    • Across your eyes (intraocular pressure) or brain.
    • On the front of your neck due to the risk of acute hypotension (through a vasovagal reflex) or even a laryngospasm.
    • Through the chest (using a front and rear of chest wall electrode positions). Either side of your spinal column is permitted.
    • Across an artificial cardiac pacemaker (or another indwelling stimulator, implantable cardioverter-defibrillators (ICDs), including across its leads) due to a risk of interference and failure of the implanted device. Serious accidents have been recorded in cases when this principle was not observed. 
    • On open wounds or broken skin areas (although it can be placed around wounds.
    • Over a malignant tumour ( experiments where electricity promotes cell growth).
    • Directly over the spinal column (although it can be placed either side of your spinal column).
    • Over mucosal membranes or internally, except for specific applications of dental, vaginal, and anal stimulation that employ specialised TENS units.
    • Head or neck of stroke or epilepsy patients.
    • Pregnant uterus.
    • On areas of numb skin/decreased sensation TENS should be used with caution because it's ly less effective due to nerve damage. It may also cause skin irritation due to the inability to feel currents until they are too high.
    • Areas of Infection. There's an unknown level of risk when placing electrodes over an infection (possible spreading due to muscle contractions). Cross contamination with the electrodes themselves is of greater concern eg dermatological conditions.

    News Report on TENS Machines: http://youtu.be/Qr0PIq7TKcc

    Source: https://physioworks.com.au/landing/tens-machines.htm

    Transcutaneous Electrical Stimulation (TENS)

    What is a TENS Unit? + How to Use & How Does it Work

    Electrical nerve stimulation is a treatment for pain that can be used for acute pain (e.g., during labor or after surgery) or for chronic pain. It is a form of electrical energy sent in various wave forms to the nerves. When it is delivered through electrodes or patches placed on the skin, it is called transcutaneous electrical stimulation or TENS for short.

    TENS is a noninvasive way to override or block signals from the nerves to the spinal cord and brain. Pain messages may be altered enough to provide temporary or even long-lasting pain relief. Besides controlling pain, this type of electrical stimulation can also improve local circulation and reduce or eliminate muscle spasm.

    This guide will help you understand

    • who may benefit from a TENS unit
    • how a TENS unit works
    • what tto expect with a TENS unit

    Who may benefit from a TENS?

    TENS can be used for relief of pain associated with a wide variety of painful conditions. This may include back pain caused by spine degeneration, disc problems, or failed back surgery. Nerve pain from conditions such as chronic regional pain syndrome (CRPS) and neuropathies caused by diabetes or as a side effect of cancer treatment may also be managed with TENS.

    TENS has been used for people suffering from cancer-related pain, phantom-limb pain (a chronic pain syndrome following limb amputation), and migraine or chronic tension-type headaches.

    TENS can also be used for muscle soreness from overuse, inflammatory conditions, and both rheumatoid and osteoarthritis. Athletes with painful acute soft tissue injuries (e.g., sprains and strains) may benefit from TENS treatment.

    Sometimes it is used after surgery for incisional or post-operative pain from any type of surgery (e.g., joint replacement, cardiac procedures, various abdominal surgeries, cesaerean section for the delivery of a baby). Studies show that TENS can significantly reduce the use of analgesics (pain relievers, including narcotic drugs) after surgery.

    TENS is usually used along with other forms of treatment and pain control such as analgesics, relaxation therapy, biofeedback, visualization or guided imagery, physical therapy and exercise, massage therapy, nerve block injections, and/or spinal manipulation.

    To summarize, the benefits from TENS treatment can include:

    • pain relief
    • increased circulation and healing
    • improved sleep pattern
    • decreased use of pain relievers or other analgesic drugs
    • increased motion and function

    How does a TENS work?

    TENS produces an electrical impulse that can be adjusted for pulse, frequency, and intensity. The exact mechanism by which it works to reduce or even eliminate pain is still unknown.

    It is possible there are several different ways TENS works. For example, TENS may inhibit (block) pain pathways or increase of the secretion of the pain reducing substances (e.g.

    , endorphins, serotonin) in the CNS.

    Electrical nerve stimulation is a treatment for pain that is used primarily for chronic pain. The electrical stimulation is delivered through electrodes or patches placed on the skin. The technique and the device used is called transcutaneous electrical neurostimulation or TENS for short.

    TENS is a noninvasive way to override or block signals from the nerves to the spinal cord and brain. Pain messages may be altered enough to provide temporary or even long-lasting pain relief. Besides controlling pain, this type of electrical stimulation can also improve local circulation and reduce or eliminate muscle spasm.

    Recent research has also shown that autosuggestion or the placebo effect is a powerful way many people experience pain relief or improvement in symptoms. Simply by believing the treatment (any treatment, including TENS) will work has a beneficial effect on the nervous system. Many studies have shown that people get pain relief through the placebo effect alone.

    How do I use my TENS unit

    You will be shown how to use your TENS device by your healthcare provider trained in the set-up and use of this modality. Round or square rubber electrodes are applied to the skin over or around the painful area. Usually four electrodes (two pairs) are used to get maximum benefit from this treatment.

    The electrodes are self-adhesive with a protective layer of gel built in to prevent skin irritation or burning. The unit is battery-operated with controls you manipulate yourself to alter the strength of the electrical signal. The unit can be slipped into a pocket or clipped to your belt. You may use two or four electrodes.

    The electrodes will be placed on your body at positions selected by a physician or physical therapist. The electrode placement is determined the location of the involved nerves and/or the location of your pain.

    The first place to try the electrodes is either directly over the painful area or on either side of the pain. You will slowly turn up the intensity of the unit until you feel a buzzing, tingling, or thumping sensation strong enough to override the pain signals.

    If that doesn’t work, you may get better results putting the electrodes over the area where the spinal nerve root exits the vertebra. Sometimes it takes a bit of trial and error to find the right settings and best electrode placement for you.

    Be sure and let your healthcare provider know if you experience increased pain. Electrodes placed below the level of a peripheral nerve impairment might actually block the input from the TENS unit and cause increased pain. Or placement over an area of scar tissue from surgery can cause increased skin resistance and decreased transmission of the electrical impulses.

    Another way to use TENS is over spots in the muscles that trigger pain called trigger points (TrPs). Trigger points are areas of hyperirritability in the muscles that can cause chronic pain.

    The healthcare provider will identify any TrPs present during your exam. Usually TrPs are taken care of with a treatment designed to eliminate them. In some patients they are chronic and don’t go away or come back easily.

    In such cases, TENS may be helpful.

    Your health care team will guide you through the trial-and-error process for finding the best electrode placement for you and make any changes needed in the program.

    When you should NOT use TENS

    • If you have loss of skin sensation or even decreased sensation, you should not use TENS. With altered sensation, there is a risk of turning the unit up too high and causing injury or harm.
    • The use of TENS is not recommended for older adults with Alzheimer’s, dementia, or other cognitive problems.
    • If you have a cardiac pacemaker, you should not use TENS as the electrical signals could interfere with your pacemaker. Cardiac patients should not use TENS without their physician’s approval.

    Some guidelines when using TENS

    • Before applying the electrodes, it is important to remove all lotions, oils, or other applications to the skin. You may want to shave hair from the local area where the electrode will be applied.
    • Daily use of TENS for several hours at a time is recommended. You should not wear the unit for long periods of time (e.g., 24 hours) or during extended sleep time (napping is okay but TENS should not be used while sleeping at night or for more than a couple of hours).
    • Never place an electrode over an open wound or area of skin irritation. Report any skin problems or burns immediately.
    • Do not place electrodes near your eyes or over your throat.
    • Do not use TENS in the shower or bathtub.
    • Move the electrodes a bit each time you put them on to avoid skin irritation.
    • You should experience a comfortable tingling sensation that is comfortable enough to allow you to complete daily tasks and activities.
    • You may want to keep a daily journal of your pain levels, the settings you use, and a record of the medications you are taking for pain relief. By reviewing your notes, you may find the best combination of electrode placement and unit settings that gives you the most pain relief.

    What can you expect with TENS

    You should feel a mild to moderately strong tingling or buzzing sensation. Some people experience a more unpleasant sensation described as burning or prickling. Depending on the intensity and duration of your pain, you may or may not get results right away.

    It can take several days to even several weeks to get the desired results. Differences in results may occur properties of skin resistance, type of pain, and individual differences in the mechanism of pain control. Be patient and persistent. Do not hesitate to contact your healthcare provider as often as it takes to get the desired results.

    Many patients do report good-to-excellent results, first with pain control, then pain relief, and finally reduction in the use of medications. Although it doesn’t happen for everyone, some chronic pain patients are “cured” permanently from their pain.

    As each of these benefits from the TENS treatment occur, you may find yourself increasing your activity level – either with the same level of TENS usage or even with reduced frequency of use, intensity of signal, or duration (length of time the unit is turned on).

    If for any reason your pain starts to increase in frequency, duration, or intensity, don’t assume the treatment isn’t working for you.

    First, check the TENS unit for any malfunction, need to recharge, or replace the electrodes with new ones.

    If your unit is battery-operated, you may find it necessary to turn the intensity up to obtain the same sensation when the batteries are low. This should alert you to the need for battery replacement.

    Finally, be aware that some patients experience “breakthrough pain,” referring to a situation in which you get pain relief at first but then even with the TENS unit, you start to have pain once again. Turning the intensity up high enough to cause muscle contraction is an indication of breakthrough pain.

    Sometimes a different setting for the stimulator may be needed when this happens. Most units have a setting that allows for random pulse frequency, duration, and amplitude. The use of this setting helps keep the nervous system from getting used to a specific amount of stimulation and ignoring it. This phenomenon is called habituation or adaptation.


    TENS is an effective method of pain control for chronic pain when you want to maintain your normal routine of daily activities that would otherwise be hampered by too high of pain levels. TENS helps many people reduce and sometimes even eliminate the use of pain medications, thus avoiding side-effects of long-term drug use.

    Even without complete pain relief, TENS makes it possible to stay active and participate in work, family, and even recreational activities. There are no significant adverse effects from the use of TENS.

    The ability of this treatment technique to moderate pain and reduce the use of pain medications is a real benefit — especially with the potential for serious or adverse effects from long-term use of pain relievers.

    Source: https://eorthopod.com/transcutaneous-electrical-stimulation-tens/

    What Does A TENS Unit Do For Muscles? (And What Doesn’t It Do?)

    What is a TENS Unit? + How to Use & How Does it Work
    There are many questions surrounding the use of transcutaneous electrical nerve stimulation (TENS) units on muscles.

    In short, TENS units aren’t considered to be the best and most effective tool for muscles but they can have their uses. In this article we delve into what a TENS unit does (and doesn’t do) for muscles.

    Be aware, if you’re reading this there’s a chance that you’re thinking of an electric muscle stimulator (EMS) machine, a very similar looking device.

    Confused About The Difference Between TENS And EMS?

    Many people confuse TENS with electrical muscle stimulation (EMS). While TENS and EMS units can look almost identical, the two have completely different purposes so it’s imperative that you choose the correct type of device.


    While TENS stimulates the sensory nerve endings – with the objective being to provide pain relief – EMS stimulates muscle motor nerves causing muscle contraction.

    In some cases if the electrode pads are placed correctly on a muscle and used on a high setting, a TENS device may cause the muscles to twitch and contract, however this is not the intention of TENS therapy and not what the devices have been designed to do.

    TechCare’s Plus 24, they tend to have names derived from massage techniques such as kneading, Swedish, and scraping, to name but a few.


    In spite of that (and perhaps surprisingly) there is a body of evidence that supports the use of TENS for certain muscular conditions and situations. We’ll come onto that a little later in the article.

    Typically, electric muscle stimulators (PowerDot being a great example) come with programs that stimulate the muscles for both exercise preparation and recovery, along with programs for strength, resistance, and endurance.

    Such programs on EMS units target either or both slow-twitch and fast-twitch muscle fibers, depending on their purpose.


    Then there are combination units on the market, such as iReliev’s PlayMakar that offer both TENS and EMS capabilities:


    A study carried out in 1997 investigated the effectiveness of electrotherapy on myofascial trigger points (knots) in patients’ shoulders (upper trapezius).

    It looked at how 60 people (25 males and 35 females) responded to electrical nerve stimulation, electrical muscle stimulation, and placebo treatments.

    EMS was found to improve the range of motion, which was measured by recording a neck side bend before and after the treatment.

    But does a TENS unit relax muscles?

    The mild electrical impulses from TENS can reduce the pain signals going to the brain, which may relieve pain and relax muscles.

    In fact, a more recent (but very small) study with fifteen healthy young males found TENS combined with stretching to be effective in reducing pain and decreasing muscle hardness, leading to an increase in range of motion.

    Muscle Knots

    Perhaps surprisingly to some, the aforementioned study into the effectiveness of electrotherapy for muscle knots found electrical nerve stimulation to be more effective than electrical muscle stimulation for the immediate relief of myofascial trigger point pain.

    Don’t confuse this with breaking up the knotted muscle tissue though:

    From my own personal experience (if it’s not practical or possible to see a physical therapist or masseuse) I have found a powerful handheld electric massager to be more effective than either TENS or EMS for getting into muscle knots.

    Muscle Spasms

    Physical therapists and physicians often recommend their patients try a TENS unit for muscle spasms.

    According to the NHS, TENS may be able to help reduce muscle spasms caused by conditions such as: arthritis, period pain, knee pain, back pain, and sports injuries.

    That being said, solid evidence for treating general muscle spasms seems to be hard to come by, although studies have looked into TENS for specific conditions.

    A big review carried out by the Center for Psychiatric Rehabilitation looked into spasticity after spinal cord injury (SCI).

    The review referenced a study that used stimulation to a nerve in the leg which led to a decrease in muscle spasms, however it did go on to say further study is required to establish whether this would work in the same ways for people with different levels and completeness of injury.

    Another noteworthy study used TENS to treat patients with muscle spasm after the lesion of upper motor neurone.

    Muscle Recovery

    In 2007 researchers at Lagos State University College of Medicine conducted a study into the relief of Delayed-Onset Muscle Soreness (DOMS).

    They examined how simple stretch exercises and trans-cutaneous electrical nerve stimulation (TENS) compared in the treatment of DOMS.

    A small but intriguing 2011 study looked into the effectiveness of three different between-inning recovery methods on baseball pitching performance.

    The authors wanted to determine which of three forms of recovery were the most effective. They compared passive recovery, active recovery, and electromuscular stimulation (EMS).

    The most notable finding was that EMS produced the highest reduction in blood lactate (lactic acid) levels. The other recovery methods had no significant effect on blood lactate.

    (Reducing the amount of blood lactate post-workout is beneficial for the recovery of muscles).

    Interestingly though other studies have found light exercise (such as swimming or jogging at a slow pace) to be more effective in blood lactate clearance.

    An example of this being a comparison that pitted submaximal swimming against muscle stimulation after sprint swimming.

    This therefore begs the question:

    Why not just do light exercise for recovery and to clear blood lactate?

    It’s not always practical. You may be physically and / or psychologically exhausted. It might be late at night. You may not have access to a pool.

    Electric muscle stimulation can make your body produce the muscle contractions required to clear blood lactate and can be used at your own discretion, when and where you .

    The Verdict

    There is research that supports the use of electrotherapy for muscles (both TENS and EMS modalities). However it’s not as conclusive as we’d . More comprehensive studies and trials would be welcome in this field.

    It might just be a case of seeing for yourself, depending on your objectives. If it is something you are considering there are many inexpensive machines for TENS and for EMS.

    Alternatively, for dealing with tight or knotted muscles at home it might be worth looking at an electric massager or a foam roller.

    Still not sure?

    You can always stick with the more traditional methods such as stretching, light exercise, and massage!

    Want to find out more?

    There are plenty of posts on the site about TENS and EMS. Click on the links below to see them:

    Source: https://www.thegoodbody.com/what-does-a-tens-unit-do-for-muscles/

    TENS Therapy For Pain Relief: Everything You Need To Know!

    What is a TENS Unit? + How to Use & How Does it Work

    Home/Pain Management/TENS Therapy for Pain Relief: Everything You Need to Know!

    Transcutaneous electrical nerve stimulation (TENS) therapy is the most widely used type of electrotherapy for the management of both chronic and acute pain.

    The therapy is administered through a TENS unit (a small battery-operated device) that has leads connected to sticky pads (electrodes), although wireless versions are becoming increasingly popular.

    A mild electrical current is sent from the device to the pads, providing a drug-free treatment option for a number of conditions including back pain and labor pains.

    TechCare Plus 24 Modes TENS Unit – Our full review

    Can TENS therapy provide pain relief?

    Physicians and other healthcare professionals have been using TENS as a form of pain relief since the 1960s.

    While there is conflicting information on the impact of TENS, there is a growing body of significant research that shows how powerful TENS can be for pain relief.

    One of the biggest advantages is the fact that it’s a drug-free way to relieve pain.

    TENS therapy is therefore ideal for those who can’t take prescribed pain medication, or choose not to due to the side effects.

    TENS is typically used in combination with other treatments to help manage pain.

    Though not a cure, it can help you treat the root cause of the problem.

    Confused About The Difference Between TENS And EMS?

    Many people confuse TENS with electrical muscle stimulation (EMS). While TENS and EMS units can look almost identical, the two have completely different purposes so it’s imperative that you choose the correct type of device.


    A TENS unit is designed to stimulate the nerves to help reduce both chronic and acute pain. However an EMS machine makes the muscles contract.

    EMS therefore is more commonly used for muscle building, recovery, training, rehabilitation, injury prevention and cosmetic appearance.

    You can purchase units that offer both functions, such as the one featured below:

    iReliev Wireless TENS + EMS Muscle Stimulator – Our full review

    What’s the cost of TENS therapy?

    The initial cost involves the purchase of the machine, which typically includes the device, lead wires, pads (electrodes), and the first set of batteries or a charger (if it’s rechargeable, most modern devices tend to be).

    Over the counter (OTC) TENS units can be found for as little as $20 – and in some cases – perhaps even less.

    More expensive devices can cost hundreds and even thousands of dollars.

    However price doesn’t always equate to performance so it’s worth reading a few reviews before making a purchase.

    In terms of maintenance, pads need replacing after a certain number of uses or when they wear out, and of course non-rechargeable devices need replacement batteries.

    Did You Know?

    In 1772, John Birch, an English surgeon, used electrical current to control pain. He later founded the Electrical Department at St Thomas’ Hospital, London.

    Do you need a prescription to try TENS therapy?

    Even though TENS machines can be purchased without a prescription (in many countries, the USA, Canada, and UK), there are a few individuals who should not use them.

    For this reason, it is best to first seek the advice of a medical professional (e.g. a doctor, physical therapist or chiropractor).

    Medical sources and TENS manufacturers tend to list similar warnings about who should not use the devices.

    However, they are very rarely identical, which is why you should always speak to a health professional.

    As an example, the NHS website (the UK’s National Health Service) states that people with a pacemaker (or any other type of electrical or metal implant in their body) should seek medical advice before using a TENS unit.

    It says the same for anyone who is pregnant, has epilepsy or a heart rhythm disorder.

    Certain TENS manufacturers also advise that anyone who has recently undergone a surgical procedure, or has cancer or any other health condition should not use the unit without speaking to a physician.

    So if you’re in any doubt about suitability it’s certainly worth checking before you begin.

    Most people who use TENS do so without experiencing any side effects.

    However, in the past it was common that a very small number of users may have an allergic skin reaction to the pads (approximately 2-3%).

    To counter this, manufacturers have moved to special latex-free pads. If you do have allergies, you should still always check the material of the pads before use.

    Other side effects from a TENS unit are often down to people not following the guidance and overusing the device or having the intensity set too high.

    Using the machine too much can make the area being treated sore.

    While using excessive intensity can make muscles twitch and result in unpleasant sensations.

    If you use the machine as advised by your physician and the manufacturer, it’s unly you’ll experience any side effects.

    A channel has two pads, and both are required for your TENS unit to work. This is because a positive charge is sent through one pad and a negative charge through the other.

    Single channel machines can be used with two pads, and you don’t have the option to add more pads.

    Most people opt for a dual channel TENS unit, meaning you can choose either two or four pads. It gives you the flexibility to treat two areas of your body at the same time.

    Some devices (such as iReliev’s Wireless TENS + EMS Muscle Stimulator) even have four channels, known as quad channel, allowing eight pads so you can treat a larger area, or eight different pain points!

    There isn’t actually a difference. Some manufacturers opt to use the term programs, whereas others use modes. They all generally refer to the same thing, a preset type of TENS therapy.

    You’ll find that most modern TENS units are now rechargeable. They tend to be higher priced however over time they will probably cost less to run as you won’t need to replace the batteries.

    Of course you do have to remember to charge your device, but with many portable power banks available on the market it can be a minor consideration.

    Nearly all dual channel TENS machines have independent intensity controls for each channel. This allows you to increase and decrease the strength of your treatment on each individual channel.

    It’s a great option when you’re treating two areas at the same time, as it might be that you need a strong intensity on just one area.

    Essentially this means you can run separate programs on different channels, rather than just different intensities.

    This feature can found in a selection of HealthmateForever’s machines, and is ideal if you have different types of pain.

    In the example below the Acupuncture mode has been selected in channel 1, with an intensity level of 15.

    While in channel 2, the Tapping mode is being run with the intensity set to level 8.

    No. People tend to think the number of intensity levels reflect the power of the device, however this is a common misconception.

    To put it simply, the intensity levels are the stages or increments that the machine can go through, the volume control on your television.

    If you have 10 intensity levels you’re going to be adjusting the power output by 10% each time. With 20 levels it’d be a 5%, 25 levels would be 4%.

    Here’s a diagram to help explain:

    The more intensity levels you have, the greater your control over the power output.

    With a higher number of levels you have more chance of finding the intensity that works best for you.

    For example if you have a machine with 10 levels, level 7 might not feel powerful enough but level 8 might feel too strong.

    However if you have 20 intensity levels, on a machine with the same power output, you’d effectively be able to get to level 7.5.

    We’ve looked closely at devices, comparing features including intensity levels, to help you make your decision.

    Sign-up for The Good Body mailing list and be the first to receive our latest news!

    Contents What is TENS therapy?Can TENS therapy provide pain relief?What’s the cost of TENS therapy?Do …

    Source: https://www.thegoodbody.com/tens-therapy/

    Back Pain TENS Treatment: TENS Belt Benefits

    What is a TENS Unit? + How to Use & How Does it Work

    • How TENS Might Help Back Pain
    • Using TENS

    TENS, or transcutaneous electrical nerve stimulation, is a back pain treatment that uses low voltage electric current to relieve pain.

    TENS is typically done with a TENS unit, a small battery-operated device. The device can be hooked to a belt and is connected to two electrodes. The electrodes carry an electric current from the TENS machine to the skin.

    There is little research to support how — or even if — TENS really works. Its use dates back to the 1960s with the introduction of the gate control theory of pain.

    According to the theory, stimulating nerves closes a “gate” mechanism in the spinal cord, and that can help eliminate the sensation of pain. During a TENS treatment for back pain, electrodes are placed on the skin over an area of pain in the back.

    This creates electrical impulses that travel along nerve fibers and create a tingling sensation. The pain relief usually starts immediately and stops shortly after treatment.

    Another theory is that stimulating the nerves may help the body produce natural painkillers called endorphins.

    Research, though, has for the most part failed to support the use of TENS alone for back pain. In one review of four studies comparing TENS to placebo, conflicting evidence made it difficult to determine whether TENS is beneficial in reducing back pain intensity.

    TENS, when properly used, is generally safe. If you think you would to try TENS for back pain, speak to your doctor. The technique works differently for different people, and it's not for everyone. Your doctor may advise against using TENS if you have a pacemaker or you are in the first weeks of a pregnancy.

    Before starting TENS, have your doctor or physical therapist show you how to use the TENS machine. Be sure to follow directions carefully and take these precautions:

    • Use TENS only for the reason your doctor orders it. Let your doctor know if your condition changes.
    • Do not leave electrodes in place for long periods of time without checking and cleaning the skin beneath them.
    • If a rash or burn develops beneath the electrodes and lasts more than six hours, stop TENS. Also call your doctor or physical therapist.
    • Do not place electrodes on broken or irritated skin.
    • Do not drive while using a TENS unit.
    • Do not use the device in the shower or bathtub.
    • Do not use a TENS unit with heating pads or cold packs.
    • Do not use TENS while sleeping.


    NYU: “Transcutaneous electrical nerve stimulation (TENS).”

    Cedars-Sinai Medical Center: “Nonsurgical Treatments for Spine Conditions.”

    ArthritisToday.org: “Non-Drug Treatments to Ease Osteoarthritis Pain.”

    Walnut Creek Chiropractic: “BV Medical Back Pain Relief TENS Support Belt.”

    Macalester College: “Conventional Pain Treatments.”

    The Cochrane Collaboration: “Transcutaneous electrical nerve stimulation (TENS) versus placebo for chronic low-back pain.”

    The Ohio State University Medical Center: “TENS (Transcutaneous Electrical Nerve Stimulation).”

    Chou, R. Annals of Internal Medicine, October 2, 2007.

    © 2020 WebMD, LLC. All rights reserved. Sciatica Pain Relief

    Source: https://www.webmd.com/back-pain/guide/tens-for-back-pain

    Transcutaneous Electrical Nerve Stimulation (TENS)

    What is a TENS Unit? + How to Use & How Does it Work

    Transcutaneous electrical nerve stimulation (TENS) therapy involves the use of low-voltage electric currents to treat pain. A small device delivers the current at or near nerves. TENS therapy blocks or changes your perception of pain.

    Transcutaneous electrical nerve stimulation (TENS) is a therapy that uses low voltage electrical current to provide pain relief. A TENS unit consists of a battery-powered device that delivers electrical impulses through electrodes placed on the surface of your skin.

    The electrodes are placed at or near nerves where the pain is located or at trigger points.

    How does transcutaneous electrical nerve stimulation (TENS) work?

    There are two theories about how transcutaneous electrical nerve stimulation (TENS) works.

    One theory is that the electric current stimulates nerve cells that block the transmission of pain signals, modifying your perception of pain.

    The other theory is that nerve stimulation raises the level of endorphins, which are the body’s natural pain-killing chemical. The endorphins then block the perception of pain.

    What is transcutaneous electrical nerve stimulation (TENS) therapy used to treat?

    TENS therapy has been used or is being studied to relieve both chronic (long lasting) and acute (short-term) pain. Some of the most common conditions for which TENS has been used include:

    For what types of conditions and areas of the body should transcutaneous electrical nerve stimulation (TENS) therapy not be used?

    Do not use TENS therapy at these specific body locations if you have any of the following conditions:

    • An implantable device (cardioverter/defibrillator, neurostimulators, bone growth stimulator, indwelling blood pressure monitors). Do not use TENS therapy over or close to the areas where an electronic device is implanted. TENS could cause these devices to malfunction.
    • Are pregnant. Do not apply TENS therapy to the abdomen; pelvic area; lower back; or to acupuncture points at the knee, hand or ankle. (However, TENS can be used for labor pain.)
    • Cancer. Do not apply electrodes to areas of the body where there is known or suspected cancer. Do not use TENS if you have undiagnosed pain and a history of cancer in the last 5 years.
    • Epilepsy. Do not apply electrodes to your head, neck or shoulders. The impulses could cause seizures.
    • Deep vein thrombosis or thrombophlebitis. Do not use TENS therapy as it may increase blood circulation, which may increase the risk of dislodging a blood clot.
    • A bleeding (hemorrhagic) disorder or recent or actively bleeding tissue. TENS therapy could increase bleeding at the tissue site or increase the risk of bleeding in persons with bleeding disorders.
    • Heart disease. Do not apply TENS therapy to the chest if you have heart disease, heart failure or arrhythmias.

    In addition, TENS should not be applied:

    • To infected tissues, wounds due to osteomyelitis or if you have tuberculosis. TENS therapy may result in the spread of infections.
    • To areas of tissue that have been recently treated with radiation.
    • To damaged skin (Except for open wounds where the intent is to use electrical stimulation to heal tissue. In these cases, therapy should be guided by a skilled therapist.)
    • Near or over eyes or mouth, front or side of neck, or on the head.
    • Near reproductive organs or genitals.
    • To areas of the body that lack or have reduced sensation.
    • In persons who have trouble communicating or who have mental impairment and cannot provide feedback to ensure the safe use of TENS.

    If you have any current or past health issues, or any concerns or questions, always check with your healthcare provider before using TENS.

    Last reviewed by a Cleveland Clinic medical professional on 01/15/2020.


    Source: https://my.clevelandclinic.org/health/treatments/15840-transcutaneous-electrical-nerve-stimulation-tens

    TENS (transcutaneous electrical nerve stimulation)

    What is a TENS Unit? + How to Use & How Does it Work

    Transcutaneous electrical nerve stimulation (TENS) is a method of pain relief involving the use of a mild electrical current.

    A TENS machine is a small, battery-operated device that has leads connected to sticky pads called electrodes.

    You attach the pads directly to your skin. When the machine is switched on, small electrical impulses are delivered to the affected area of your body, which you feel as a tingling sensation.

    The electrical impulses can reduce the pain signals going to the spinal cord and brain, which may help relieve pain and relax muscles. They may also stimulate the production of endorphins, which are the body's natural painkillers.

    TENS may be able to help reduce pain and muscle spasms caused by a wide range of conditions including:

    It's also sometimes used as a method of pain relief during labour.

    There isn't enough good-quality scientific evidence to say for sure whether TENS is a reliable method of pain relief. More research is needed and clinical trials for TENS are ongoing.

    Healthcare professionals have reported that it seems to help some people, although how well it works depends on the individual and the condition being treated.

    TENS isn't a cure for pain and often only provides short-term relief while the TENS machine is being used.

    However, the treatment is generally very safe and you may feel it's worth trying instead of, or in addition to, the usual medical treatments.

    If you're thinking about trying TENS, it's a good idea to speak to your GP about a referral to a physiotherapist or pain clinic.

    A physiotherapist or pain specialist may be able to loan you a TENS machine for a short period if they think it could help.

    You can choose to buy your own TENS machine without getting medical advice, but it's generally better to have a proper assessment first, so you can find out whether a TENS machine is appropriate for you and be taught how to use it properly.

    To get the most benefit from TENS, it's important that the settings are adjusted correctly for you and your individual condition.

    If you find TENS effective, you can buy a TENS machine from a pharmacy. They range in price from about £10 to £200. More expensive machines aren't necessarily any better than lower-priced ones, so it's best to do some research before you buy.

    The information below is a general guide on how to use a TENS machine. You should always follow the manufacturer's specific instructions.

    TENS machines are small and lightweight, so you can use them while you're working or on the move. You can put it in your pocket, clip it to your belt or hold it in your hand.

    You can use TENS throughout the day for as long as you , although it shouldn't be used while you're driving, operating machinery, or in the bath or shower. 

    Positioning the pads

    Make sure the machine is switched off before you attach the pads to your skin. Position the pads either side of the painful area, at least 2.5cm (1 inch) apart.

    Never place the pads over:

    • the front or sides of your neck
    • your temples
    • your mouth or eyes
    • your chest and upper back at the same time
    • irritated, infected or broken skin
    • varicose veins 
    • numb areas

    Turning it on and adjusting the strength

    Turn on the TENS machine when the pads are attached in the correct places. You'll feel a slight tingling sensation pass through your skin.

    The machine has a dial that allows you to control the strength of the electrical impulses.

    Start on a low setting and gradually increase it until the sensation feels strong but comfortable. If the tingling sensation starts to feel painful or uncomfortable, reduce it slightly.

    Switch the TENS machine off after you've finished using it and remove the electrodes from your skin.

    For most people, TENS is a safe treatment with no side effects.

    Some people may be allergic to the pads and their skin may become red and irritated, but special pads for people with allergies are available.

    TENS isn't safe for everyone to use. Don't use it without first seeking medical advice if:

    • you have a pacemaker or another type of electrical or metal implant in your body
    • you're pregnant, or there's a chance you might be pregnant – TENS may not be recommended early in pregnancy
    • you have epilepsy or a heart problem

    Source: https://www.nhs.uk/conditions/transcutaneous-electrical-nerve-stimulation-tens/