The 2020 Ultimate Guide to TENS Units
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If you’re looking for pain relief, you may have considered or had TENS units recommended to you. They’re incredibly popular nowadays, and many people swear by them to relieve all different kinds of ailments. But if you’re new to TENS therapy, it can be overwhelming to try to research what it is and if it’s a good fit for you in particular.
This guide will walk you through everything you need to know about TENS units, including what they are, how to use them, and how to find the best unit for you.
What is a TENS Unit?
A transcutaneous electrical nerve stimulation (TENS) unit is a small, battery-operated device used to relieve and manage acute and chronic pain. It is the most common form of electrotherapy, administering mild electric shocks to the body's affected area through adhesive pads called electrodes. The electrodes are placed on the skin and are typically connected to the TENS unit with lead wires, though wireless options are also available.
How do TENS Units Relieve Pain?
Put simply, the electric shocks that the TENS unit administers stimulates the body’s nerves. This helps relieve pain in two ways: by releasing endorphins and pain gating.
Stimulating the body’s nerves can help activate and release endorphins. Endorphins are one of many neurotransmitters or brain chemicals that transmit messages between cells. These signals enable our bodies to function correctly and affect how we perceive the world around us.
Endorphins, specifically, are released when our bodies experience pain or stress. When released, they reduce pain and make us feel happier, and enhance our immune response. Endorphin release can be achieved with pain medication. But TENS units have the same effect without the risk of addiction or dependence.
To experience pain and other sensations, our body’s nerve fibers send sensory signals to the spinal cord, which then sends the signals up to our brain so we can perceive the sensation. Large nerve fibers send signals when we experience normal touch or pressure, while small nerve fibers send pain signals when we’re injured. Our ability to perceive pain depends on the brain receiving the pain signals and decoding them into the feeling of discomfort, etc.
In the early 1960s, Ronald Melzack and Patrick Wall proposed the idea of “pain gating,” or gate control theory. This is the idea that before your brain can receive pain signals, a “pain gate” at the end of the spine allows or blocks the signals from passing through to the brain. For some injuries, the signals pass easily, and we feel intense pain. In other cases, the signals may be inhibited or stopped entirely.
Activating the large nerve fibers with normal sensations can help inhibit the pain signals sent by the small nerve fibers and help relieve pain. This is why we often rub or shake an injured body part, and why TENS units work! TENS units activate the large nerve fibers by creating a tingling or massaging sensation on the injured area, which blocks pain signals and temporarily reduces our perception of pain.
How Long Does the Relief Last?
After using a TENS unit, pain relief can last anywhere from 5 minutes to 24 hours. It’s hard to say precisely why it varies so much. Still, it’s been suggested that the amount of relief depends on the type and intensity of the pain. For example, someone with acute pain may experience more prolonged periods of relief than someone with chronic pain, who might go back to their normal pain levels shortly after turning off the device.
Regular use of a TENS unit can sometimes lead to longer relief periods. Over time it can also cause you to build up a tolerance to the treatment. To prevent your nervous system from getting too accustomed to electrotherapy, take breaks between treatment sessions, or change the position of the electrodes.
TENS Unit vs. EMS
TENS units are not to be confused with EMS (electrical muscle stimulation) devices. However, they are very similar; both portable devices deliver mild electric shocks through electrodes. Each is used for a different purpose.
While TENS units stimulate the nerves, EMS units stimulate the muscles and cause them to contract. Stimulating the muscles helps strengthen and tone, as well as relax and rehabilitate them. If you’re looking to build muscle as part of a training program, an EMS unit is the device for you! But if you’re mainly looking to relieve acute or chronic pain, you will want to make sure you purchase a TENS unit.
Looking to relieve pain and build muscle? There are some combination devices available with both TENS and EMS functionality. They are often more expensive than a standard TENS or EMS unit, but they can be a worthwhile investment if you plan to benefit from both treatments.
History of TENS Therapy
It may surprise you to learn that TENS therapy is not technically a new method of pain relief. As far back as 2500 BC, people would use electric eels or fish to help manage pain. Even Hippocrates, the father of western medicine, treated the people of ancient Greece with this method.
As time went on, more discoveries were made that developed electrotherapy as a treatment method. In the 1600s, man-made electricity was discovered and studied. In 1747, Ben Franklin found that electricity could penetrate the body without damaging it. These discoveries paved the way for the development of dozens of first TENS machines in the 1800s. However, those devices (and electrotherapy as a whole) became largely irrelevant with the emergence of narcotic painkillers.
So what caused TENS therapy to make a modern comeback? Here’s a brief overview:
- 1964: Melzack and Wall’s gate control theory helps explain why electrotherapy relieves pain. This breakthrough causes electrotherapy to reemerge into modern medicine.
- 1974: American Neurosurgeon Clyde Norman Shealy patents the first version of today's TENS unit. Following his invention, TENS therapy becomes more popular.
- 1987: Ray Kriesler invents a TENS device specifically to be used during labor. This invention helps mothers who do not respond to traditional forms of labor pain relief, such as an epidural and allows for a less painful natural birth.
- 1987 - Present Day: Many studies are done to show that TENS units are effective treatments for a wide variety of acute and chronic ailments. Modern variations of Shealy’s original invention are created so anyone can find the best TENS unit for their specific needs.
Why Use a TENS Unit?
With so many pain relief options, you may still be on the fence about whether TENS therapy is the best choice for you. If that’s the case, consider the following benefits to using a TENS unit that set it apart from the rest:
Drug-Free Pain Relief
TENS therapy is all-natural and drug-free, helping you manage pain without the risk of dependence or dangerous side effects. This makes it a safe alternative or supplement to prescription drugs and other treatment methods. See the “Are TENS units safe?” section for more information about safety and side effects.
Because there are very few risks or side effects, you can manage your pain with a TENS unit as frequently and as long-term as you need to.
TENS units are effective in managing a wide variety of chronic and acute pain. Although you’ll probably purchase a TENS unit to manage a specific ailment, it could help relieve other unrelated pain, such as headaches or menstrual cramps. See the “What are TENS units used for?” section for more information on its versatility.
TENS units allow you to have more control over your treatment than other options. There will be multiple modes and intensity levels to choose from on your TENS device, and you’ll get to decide how long each treatment session will last based on your needs.
TENS units are small enough to fit in your pocket or clip to your belt so that you can bring them wherever you go. The subtle size and noninvasive electrodes also make it easy to use in public discreetly.
Easy to Use
TENS units may sound fancy and complicated, but they’re just as easy to use as an ice pack or heating pad. With a simple control panel and self-adhesive electrodes, you’ll get the relief you need without any hassle.
TENS units are one of the most affordable treatment methods available, with just a one-time purchase of $20 to $200 depending on its features and about $10 to $15 every few months to replace your electrodes.
Over-the-Counter (OTC) Option Available
Although we recommend seeing a doctor to determine if TENS therapy is an option for you, a doctor’s prescription is often unnecessary. There are many over-the-counter TENS units available to the public.
What Experts Say About TENS Therapy
We reached out to numerous health professionals including physical therapists, prescription doctors, and health experts to offer their advice, experience, and expert opinions on TENS therapy as a method of pain relief.
General Practitioner & Family Doctor at Prescription Doctor
"Tens machines can be hit or miss depending on the person. If your pain is on the surface level and something that does not affect you everyday, a tens machine could be the right thing for you, instead of taking medication such as paracetamol or ibuprofen. If your pain is chronic however, I would suggest that you think about other treatment and not a tens machine. They may not be able to help the deep levels of pain, or if it is frequent. I think that as a medical professional, it is up to your discretion whether you recommend a unit or not."
Zach Walston, PT, DPT
Certified Specialist in Orthopedic Physical Therapy
"TENS units provide short-term pain relief for low back pain. The sensation experienced while using TENS essentially replaces the perception of pain. Think of TENS as a fancy method of rubbing your elbow after hitting it on the corner of the table. The effect experienced by TENS is individual as expectations influence the magnitude of pain relief. TENS, along with other modalities such as ultrasound and hot packs, rely heavily on a placebo effect. The pain reduction is real, but it is not the result of a fancy mechanism exclusive to TENS. TENS does not facilitate healing, any healing that occurs would have taken place without the TENS. I rarely recommend TENS. If the options are TENS or medication, TENS will win out every time, but there is no reason for the options to be limited. TENS will not cause direct harm, but it can create dependence and failure to implement long term strategies for pain (exercise, diet, sleep, stress, understanding of pain mechanisms, etc.)"
Angela Fishman, PT
My Pelvic Therapy, PLLC | Owner
Licensed Physical Therapist
"I use TENS on a regular basis with patients to help decrease bladder pain and improve bladder frequency and urgency complaints. It can also be effective in helping decrease nighttime trips to the bathroom. Over my 30 year career as a PT I have also used TENS for back pain, with varying degrees of success.
Why I recommend TENS units to patients:
1. Simple to use
2. Portable, so does not interfere with daily activities
3. Can provide effective pain relief with minimal side effects, such as may occur with medications. Occasional irritation at electrode sites may occur.
4. Available over the counter
5. Affordable for many
What type of ailments I typically use TENS for:
I have found TENS to be particularly effective in addressing bladder symptoms, such as bladder pain, frequency, and/or urgency. Electrodes can be placed on the lower abdomen, or on the low back, to help alleviate bladder pain that can be associated with conditions such as painful bladder syndrome and interstitial cystitis. Electrodes placed on the low back, at the level of the sacral nerves which supply the bladder, can be helpful in decreasing urinary frequency and even leakage such as with overactive bladder syndrome or urge incontinence."
"TENS machines are used by hundreds of thousands of pain sufferers all over the world for the relief of many types of physical pain from back to knee to neck pain. It is trusted global and this is why I recommend it for my patient with any major or minor pain such as acute and chronic pain, post-op incisions and post-surgical pain, labor, and delivery, migraine and tension headaches, acute pain from sports, and other injuries, arthritis, chronic pain from tendentious and bursitis, cancer pain, and wound healing."
"IMO, the best use of a TENS machine is during childbirth. TENS is deemed safe in the UK and Europe for this purpose and used in early and active labor to help manage contractions. Most women rent a TENS machine at their local pharmacy for a six week period. Use of TENS for labor and childbirth is not (yet) common in the USA however there are FDA approved TENS machines for menstrual cramps that could be used for labor as well. I used a TENS device myself in labor and found it a great experience. The only downside is that the device cannot be used when immersed in water."
"I often recommend TENs units for patient in chronic pain or experiencing high levels of pain post surgery. Neck, low back, knee and shoulder pain are the most common locations. TENs is also great on the low back region during labor for mother's that want to go the natural route.
It is a great tool to have around the house due to its small size and relatively low cost. You can find one for $20-30 dollars on Amazon and most insurance will cover costs with a MD or PT referral.
What is TENS used for?
People use TENS to relieve pain for several different types of illnesses and conditions. They use it most often to treat muscle, joint, or bone problems that occur with illnesses such as osteoarthritis or fibromyalgia, or for conditions such as low back pain, neck pain, tendinitis, or bursitis. People have also used TENS to treat sudden (acute) pain, such as labor pain, and long-lasting (chronic) pain, such as cancer pain.
Although TENS may help relieve pain for some people, its effectiveness has not been proved.
Is TENS safe?
Experts generally consider TENS to be safe, although the machine could cause harm if misused. Have your physical therapist or doctor show you the proper way to use the machine, and follow these instructions carefully.
Always tell your doctor if you are using an alternative therapy or if you are thinking about combining an alternative therapy with your conventional medical treatment. It may not be safe to forgo your conventional medical treatment and rely only on an alternative therapy."
Dr. Robert W. Berghorn, Jr., DPT, ATC, USAW
Owner, Physical Therapist
Ascent Physical Therapy, PLLC
:I have used TENS units regularly throughout my practice. As I have gone further into my career though I have used them less in my practice. I still recommend them, especially for home use and when a patient is in acute pain but during my actual, individual time with a patient I would prefer to use something that is more effective at treating the root cause of my patient's ailment.
TENS units do what they say they do...They help with pain relief. However, just like any medication you take or any injection you get, it is temporary. At a maximum it will provide about 20 minutes of relief after the machine is turned off.
The way a TENS machine works is it basically distracts your brain. As signals from out peripheral tissues (low back, leg, hands, etc.), along our nerves, and up to our brains in order to be interpreted as pain, they need to travel along pathways that are connected with other nerves. Nerve fibers that are responsible for pain travel a lot slower than your tactile or touch sensation.. Therefore, the TENS machine, itself works to stimulate your touch sensation to travel and "cut off" the message of pain to your brain. Basically, the TENS machine acts as a distraction for your brain from pain (fascinating right???).
It's the same principle that happens when you bump your head. What do you do? You rub your head. Who told you to rub your head to make it feel better?? I still don't remember who told me the first time but it follows the same principle. Stimulation of your touch sensation, prevents the pain signal from reaching the brain and in turn, you don't feel pain.
When I recommend them to my patients for use, I teach them to use it as a tool. Not as a crutch or something they need to rely on. They can use it for acute pain to help get through the initial inflammatory stages of healing or can use it when they have an acute flare up. However, they need to make sure that they are still seeking care to take care of the ORIGIN and direct CAUSE of the pain. TENS machines again are not something to become reliant on."
"As a doctor of physical therapy, I use and recommend TENS to my patients often. Using TENS can be helpful for temporary pain relief. It is a great alternative to help with pain when a patient needs immediate relief, wants relief while continuing with their daily routine and when they prefer not to use medication. It is a great way to calm down pain prior to getting my patients to start moving.
I usually recommend using TENS when my patients have acute pain (pain that began in the last 2-4 days) in a large area. I mostly use TENS on the shoulder, upper and lower back. However, it can be placed anywhere on the body that is not over the heart, implanted devices, or active tumors.
With acute pain, people often feel that they are unable to move or have difficulty moving. TENS can be easily put on while at rest (sitting or laying down) to help with pain. It can also help for those who need to continue to move, but feel limited because of pain. Many of the at-home units are portable, so it can be easily clipped onto clothing to provide relief while doing work (housework, or a laborious job)."
"At our office, we prescribe TENS units regularly for our patients. They are good for musculoskeletal pain. You can use them almost anywhere. Using them for 20 minutes at a time is a great way to reduce pain. It helps by interrupting the pain signals and can even snap a muscle out of a spasm. They are a great adjunct therapy for pain. There are also only a few restrictions so most people will benefit from the use of them.
All of our products and practices in our office are evidence based. We also have tested them on ourselves as well, so we can speak from personal experience for any service we offer for our patients."
"I’ve used TENS units with patients who have pain. Typically, I would use on patients after a treatment session paired with heat or ice, depending on patient’s preference, level of pain, and goal of treatment. A TENS unit stimulates the touch sensation of the nervous system, which can busy the brain, to decrease its ability to perceive pain.
I recommend TENS units for three reasons:
- TENS units can reduce pain.
- TENS units are used locally on the affected body part, rather than systemically, like medication
- TENS units allow the patient to be in control of pain, which improves autonomy and ownership of recovery from an injury or surgery.
Typical ailments that patients use for a TENS unit for include: chronic pain (back and neck pain are common), acute pain related to injuries, and post op surgical pain (shoulder, knee, and ankle are common)."
"I have recommended TENS units to several family members with neck and shoulder pain. Everyone so far agrees that as long as you use the correct setting and pad size, they work very well. If they are placed in the wrong location or the wrong settings are used, TENS units can cause a tingling sensation or even a mild shock. Reading the directions or watching a video usually ensures proper use."
"I was educated on TENS in my DPT program as well as self-learning after graduation. I see it as a good non-pharmacological/surgical way to help manage acute and chronic pain that is safe for most. With the rise in ability to get TENS units online or in the store, I typically recommend the one that is most convenient for the person I am actively treating to help them get back to their activities or be able to manage more chronic conditions."
Kyle Atwell PT, DPT, OCS, COMT, CMTPT, FAAOMPT
Managing Member, GOfit Physical Therapy LLC
"As a physical therapist the use of TENS devices is part of our routine practice.
TENS for pain relief: TENS units work to reduce pain through dorsal horn inhibition. This essentially means that the sensation created by the TENS device overrides, or inhibits, the painful sensation that the person is experiencing. This process occurs both in the peripheral and central nervous system.
We all use dorsal horn inhibition on a regular basis without even knowing it. Have you ever hit your funny bone or stubbed your toe? I bet you found yourself rubbing the injured area for some pain relief, right? If you did, you are actively performing dorsal horn inhibition, the same exact thing that a TENS machine would do.
General experience with TENS: TENS can be helpful at reducing the intensity of someone's pain. TENS however won't fix the cause of the pain only mask the symptoms so to speak. This can still be beneficial as it may allow for other treatments that can directly affect healing.
Another benefit is that by reducing the intensity of pain the patient may experience less fear avoidance behaviors, something critical to long term prognosis.
When TENS works best: TENS can be used when someone is experiencing both a new onset of pain (acute) and persistent pain. TENS typically works best when the pain is moderate. If the pain is too severe it likely won't help or may make things worse. Likewise if the pain is fairly minimal it won't have as great of affect.
Conclusion: In general TENS can be helpful as a "distraction" for moderate pain. It certainly won't fix the cause of the pain but may allow for other treatments or for the person to become more active again."
"I have used TENS units with my patients for many years to assist with pain relief. I recommend them for a variety of medical conditions and injuries such as: chronic cervical, thoracic, and/or lumbar pain, tendonitis, ankle sprains, and sports injuries. I also often recommend them after surgical procedures such as rotator cuff repairs, total knee arthroplasty, ACL repairs, and total hip arthroplasty to help decrease pain.
My experience working with TENS units is primarily in an outpatient Physical therapy clinic setting. I use them to assist with decreasing patient's symptoms of pain and sometimes issue them a home TENS unit for symptom management of pain at home. They are conveniently small and patients can wear the unit in their pocket and still be able to walk around their house."
OTC vs. Prescription
While OTC TENS units are available and widely used, some TENS units require a prescription from your doctor. The main differences between over-the-counter and prescription devices are their intensity levels and treatment modes. Typically, prescription TENS units offer higher intensity settings and more treatment modes, such as customizable frequencies and wave types. This allows them to target and relieve pain more precisely.
That said, prescription TENS units are often more expensive than OTC devices. Although OTC TENS units have lower intensity settings and only a few treatment modes to choose from, they are strong enough for most people. Unless your doctor believes a prescription device is necessary, a less expensive OTC unit will likely work well for you.
What Are TENS Units Used For?
Because TENS units offer customizable, targeted therapy, they can treat a wide variety of pain. Below are some of the many ailments TENS therapy can help relieve.
TENS Units for Back Pain
TENS units are widely used to treat upper and lower back pain. Still, unfortunately there is currently not enough evidence of the treatment’s effectiveness for the NHS to recommend it. One 2014 analysis found positive trends for chronic back pain, while another study found that TENS therapy acted merely as a placebo. Either way, with thousands of users finding back pain relief using TENS therapy, it’s worth trying.
One back ailment the NHS does recommend TENS therapy for is a herniated disc. Studies found it to be the most effective treatment option.
TENS Units for Neck Pain
The NHS recommends TENS units for neck pain. They can also be used to treat neck pain related to cervical spondylosis. The neck is a sensitive area, though, and TENS therapy for neck pain should be conducted cautiously. We recommend placing the electrodes right below the neck on the upper back. With this placement, electrical impulses can travel to the neck without irritating the neck's sensitive area.
TENS Units for Nerve Pain
Because TENS units block nerves from sending pain signals to the brain, TENS therapy is an excellent option for nerve pain relief. This includes pain caused by nerve damage and pain associated with sciatica and complex regional pain syndrome (CRPS) when accompanied by other treatment forms. TENS therapy is also recommended by the Brain and Spine Foundation and the Foundation of Peripheral Neuropathy to treat neuropathic pain.
In addition to general nerve pain, some studies have found TENS units to be an effective treatment for vagus nerve pain.
TENS Units for Knee Pain
Studies have shown TENS therapy to help with various knee pain, including swelling, osteoarthritis, and post-surgery pain. Physical therapists might also recommend TENS therapy to treat meniscus tears and IT band pain, often accompanied by other treatment methods such as icing the affected area.
TENS Units for Muscle Pain
TENS therapy is very commonly used as a treatment for muscle pain. It's recommended by the NHS and has been found to effectively treat sore muscles, muscle spasms, muscle knots, and muscle atrophy. TENS therapy also has a calming effect on the central nervous system, helping reduce pain related to fibromyalgia.
TENS Units for Face Pain
While it is highly advised not to use a TENS unit on your face, TENS therapy can effectively treat facial pain when conducted under proper supervision. A 2017 study found TENS therapy to be effective in treating Temporomandibular Joint Syndrome (TMJ). Additionally, a 2011 study found TENS therapy to be safe and effective in treating trigeminal neuralgia (TN). If you’re looking to use TENS therapy to treat either of these ailments, talk to your doctor first.
TENS Units for Pregnancy and Labor
TENS units have been found to be effective when treating pregnancy pain. However, the NHS does not recommend TENS therapy in the early stages of pregnancy. You should never use a TENS unit in the abdominal or pelvic regions while pregnant, and always consult with your doctor before using electrotherapy for pain relief.
TENS therapy can help relieve pain during the early stages of labor, especially in the case of home birth. The NHS recommends it and many moms believe it was more effective than other early labor pain relief.
TENS Units for Tinnitus
For some forms of tinnitus, TENS therapy can be an effective treatment method. For example, the U.S. National Library of Medicine found it to be successful in treating patients with ‘typewriter’ tinnitus. In contrast, another study found it to help those with tinnitus that worsened with neck movement.
TENS Units for Stroke Recovery
TENS therapy can also be useful in aiding in stroke recovery. One study found that using a TENS unit after experiencing a stroke can improve walking capacity and reduce spasticity. Another study found that electrotherapy can help improve movement and relieve shoulder pain post-stroke.
TENS Units for Pelvic Ailments
TENS therapy has been found to reduce pain related to ailments in the pelvic area. For example, one study concluded that TENS can effectively treat pelvic pain associated with pelvic floor dysfunction. The Interstitial Cystitis Association and The National Institute of Diabetes and Digestive and Kidney Diseases both recommend TENS for treating interstitial cystitis pain.
TENS Units for Feet Pain
TENS therapy can be incredibly useful in treating the feet with several TENS products specifically made to target foot pain available. The British Orthopedic Foot and Ankle Society recommends TENS therapy for heel pain in particular. Additionally, TENS therapy can strengthen the foot muscle to help treat foot drop.
Are TENS Units Safe?
Although sending electrical shocks to your body seems dangerous, TENS units are much safer than they sound. There have been no recorded instances of anyone being severely injured while using the device. The electric shocks delivered by the device are too weak to cause electrocution or other significant damage. The most you have to worry about is a harmless, surprising shock if you accidentally set the intensity up too high for your needs.
Most people don’t experience side effects from using a TENS unit. However, the electrical stimulation may cause a tingling or buzzing sensation that can sometimes be uncomfortable.
The electrodes can also sometimes irritate the skin and cause it to become red and itchy. This effect should go away shortly after removing the electrodes. However, if it persists, you may be allergic to the latex of the pads. Luckily, hypoallergenic, latex-free electrodes are an option.
Because of the low risk, TENS units can be used as long and as often as needed. However, professionals recommend 30-minute sessions with 20-minute breaks in between. Overuse can sometimes cause soreness, a burning sensation on the skin, or uncomfortable muscle twitching.
Who Shouldn't Use a TENS Unit?
Although TENS units are generally low risk, you should always consult your doctor before using one to ensure that it is the right choice for you. In some instances, the device can be unsafe to use. It is recommended that you do not use a TENS unit if you:
- Are pregnant. Pregnant women should avoid using a TENS unit on the abdominal and pelvic regions.
- Have epilepsy. Using a TENS unit on the head or neck can cause seizures.
- Have heart problems.
- Have a pacemaker or any electrical or metal implant.
- Have skin that is numb, irritated, or fragile.
- Are driving, using machinery, sleeping, or in the bath/shower.
Again, always consult your doctor to make sure that a TENS unit is safe for your situation.
Which TENS Unit is Best?
There are thousands of TENS units on the market, all with varying features and capabilities. On Amazon alone, a search for “tens unit” will give you 55 pages worth of options from over 50 brands, ranging from $10 to $999.99. So how do you know which one is right for you?
The number of available options can be overwhelming, especially if you have no clue what the different features mean. In this section, we’ll go over what to consider (and what it all means) so that you can find a TENS unit that’s right for you.
Electrodes are the adhesive pads that administer the electric shocks to your body. They are usually reusable, and most TENS units will come with a pack to get you started. Some electrodes have a higher quality stick than others. The most significant difference will lie in whether they are wired or wireless.
- Wired: Electrodes are most often connected to the unit using lead wires, with two pads per wire. These electrodes are more lightweight and can come with a range of wire lengths. Longer lead wires can be more comfortable and easier to use since they can reach farther.
- Wireless: Wireless electrodes can be more convenient since there aren’t any wires to get tugged on or in the way. However, these pads may be bulkier and heavier on the skin.
In addition to wired vs. wireless, it should be noted that many electrodes are made with latex. If you have a latex allergy, look for a TENS unit with hypoallergenic, latex-free pads.
The number of channels refers to the number of lead wires that can be plugged in at a time. More lead wires means more electrodes, which allows you to target more, or larger, pain areas at a one time. Typically, there are three different channel types: single, dual, and quad.
- Single: One lead wire channel; two electrodes running at once.
- Dual: Two lead wire channels; four electrodes running at once.
- Quad: Four lead wire channels; eight electrodes running at once.
The average TENS unit will feature dual channels, which is typically best for most users.
The pulse duration is the length of the pulse that the TENS unit administers. A longer duration means stronger stimulation. Most units will come with an adjustable range for maximum
The pulse rate is the rate at which the electric pulses are sent from the device, usually described in hertz or pulses per second. The pulse rate you choose will usually depend on the area of the body and the type of pain being treated. 2-10 Hz can help release endorphins to treat chronic pain, while 80-120 Hz can be best for acute pain. Like pulse duration, most units will come with an adjustable range for maximum customization.
Most TENS units will come with a preset timer that automatically shuts off, so it doesn’t run continuously. Depending on the unit, the timer may not be adjustable. You may need to restart the device for longer treatments.
Intensity levels determine how strong the treatment is. The higher the intensity level, the stronger the electrical current sent from the unit. Most TENS units go up to 80 mA, while some go up to 100 mA. What you choose depends on the type and amount of pain you feel, but most users don’t need more than 80 mA. Those with intensities higher than 80 mA are often prescription units.
Most TENS units will come with a certain amount of modes, or “presets” to choose from. These will have a predetermined pulse duration, pulse rate, timer, and intensity set for the treatment to make getting started easier. Some units might even allow you to choose different modes for different channels.
Usually, the more expensive TENS units will feature more modes. But if you’d rather customize your treatment yourself, fewer modes might not matter to you as much.
Some TENS units are larger than others, making them less subtle and less ideal for on-the-go use. Consider how often you will be using your TENS unit outside of the house. If you’ll be regularly taking it out with you, you might prefer a smaller, more portable device.
Some TENS units will come with a carrying case, extra electrodes, specialized equipment, and more. The amount of additional accessories the unit comes with will often add to the cost of the unit. What you choose is up to your budget and preferences.
TENS + EMS Combo
As we mentioned earlier, some units have both TENS and EMS capabilities. This is a great, convenient option if you want to relieve pain and strengthen muscles, but it can add more to the cost. If you’re only looking for pain relief, a simple TENS unit will work just fine.
Some TENS units use rechargeable lithium batteries while others use traditional, one-use batteries such as AAA or 9V. Rechargeable batteries can be a convenient option and save you time and money in the long run. But if you’re not interested in rechargeable batteries, traditional ones will work just as well.
Some brands have been making TENS units for years, while others are relatively new. You will want your device to be reliable, so a more established brand is sometimes best. But if you’re considering a TENS unit from a newer brand, be sure to check the reviews first.
Finding the right TENS unit for you is essential for optimal pain management and relief. Be sure to consider all of these factors before purchasing your device, and talk to your doctor or physical therapist about what might work best if you’re unsure.
How do You Use a TENS Unit?
Using a TENS unit is relatively simple, but you’ll want to do it right to get the most benefits from your device. Here’s a brief step-by-step:
- Connect lead wires to the electrodes.
- Connect lead wires to the TENS unit device.
- Clean the treatment area with soap and water.
- Place electrodes flat on the affected area. We will discuss proper electrodes placement below.
- Turn the machine on, keeping it at the lowest intensity level.
- If using a pre-set therapy mode, select the mode you desire.
- If not using a mode or need to slightly adjust it, select your desired pulse width and rate.
- Set the timer if possible.
- If using the TENS unit for the first time, be sure to adjust the intensity, mode, and pulse width and rate until reaching optimal pain relief.
How to Place TENS Unit Electrodes
Proper placement of the electrodes is essential to receiving optimal pain relief. When targeting a specific area, place the electrodes on each side of the painful area. This placement allows the electrical current to pass through the targeted area. If using four electrodes, place each pad on each side of the targeted area in a square or diamond shape.
There are some areas of the body that you should avoid placing the electrodes due to their sensitivity. These areas include:
- On the throat or neck
- Any part of your face or head
- Over the eyes
- In the mouth
- On broken, numb, sore, or infected skin
- Over a joint such as a knee, elbow, or ankle
- Over or around your heart
Suppose any of these are the painful area. In that case, you can place the electrodes around or below the area (for example, place electrodes on the upper back for headaches and neck pain) and still feel relief.
Points to Remember When Using Your TENS Unit
- Do not use your TENS unit while sleeping, driving, swimming, or in the bath/shower.
- Your muscles may twitch when using the TENS unit at high-intensity levels.
- The intensity felt may be increased if sitting back in a chair with electrodes on your back, as it increases the pads’ contact with the skin.
- If irritation occurs and persists, cease treatment, and consult your doctor.
- You may not immediately feel pain relief when the treatment begins. It’s best to start at a lower intensity and continue to increase and change modes as needed.
- TENS units are not a cure for any physical ailment. They are a tool for pain relief. It is best to continue any physical therapy or other treatment already in place while using TENS therapy.
How to Maintain Your TENS Unit
TENS units are designed for repeated use over time without very much maintenance. Still, you should always make sure the unit is not damaged and is working correctly before use. This includes checking the device itself, the electrode cords, and the batteries for leakage. Never try to use a damaged unit.
Should you need to clean your TENS unit, turn it off and disconnect and cords beforehand. Use a damp cloth (no chemicals, only water or a neutral cleaning solution) and wipe the surface gently, careful not to get water inside the device.
Store the unit in an area that is away from direct sunlight, humidity, or high voltage. If you plan to store it for an extended period, remove the device's batteries to prevent leakage.
Most electrodes are reusable and can last up to 5 to 6 months. That said, there are some things you can do to help your electrodes maintain their stickiness and last as long as possible:
- Clean your skin with soap and water before each use. The skin’s natural oils can dirty the electrode and make it less sticky.
- Clean your electrode pads with a moist towel or washcloth after each use. This helps remove dirt or oil and bring back some stickiness.
- Use a conductive gel or spray with each use to help preserve or regain the moisture of the pad.
- Store the pads in their packaging, so they don’t dry out.
It’s best to replace your electrodes once they no longer stick to your skin, or a majority of the pad is not in contact with your skin.
Frequently Asked Questions
Are TENS units covered by Medicare?
TENS units prescribed by a physician can be covered by Medicare, but only under some circumstances. Suppose you are using a TENS unit to treat acute postoperative pain. In that case, Medicare Parts B and C will cover the cost of renting the device for up to 30 days (sometimes more if exceptionally necessary).
Medicare Parts B and C will also cover a TENS unit used to treat chronic pain lasting more than 3 months as long as no other standard pain relief methods have proven effective. Initially, Medicare will cover the cost of renting the device for 30 to 60 days. If your physician certifies that the device will likely provide you with long-term pain relief, Medicare will cover the cost of purchase.
Unfortunately, this does not include TENS units for chronic back pain, headaches, internal abdominal pain, TMJ pain in the jaw or face, or other pain types that do not typically respond to TENS treatment.
Are TENS units FSA eligible?
Yes, OTC TENS units are eligible for purchase or reimbursement with a flexible spending account (FSA), health savings account (HSA), or health reimbursement arrangement (HRA)! Unfortunately, they are not eligible for reimbursement with a limited care flexible spending account (LCFSA) or a dependent care flexible spending account (DCFSA).
About the Author
Stephanie Schwarten is a freelance writer and editor with a Bachelors degree in Professional Writing. She specializes in content marketing as well as both developmental and copy editing.
About Carex Health Brands
Carex is your one-stop shop for home medical equipment and for products that assist caregivers with providing the best possible support and care for their loved ones. Carex Health Brands has been the branded leader in in-home, self-care medical products for over 35 years. Our goal is to improve the lives of our customers by bring them quality products that bring dignity back to their lives. With our three nationally distributed brands, Carex Health Brands serves national, regional and independent food, drug and mass retailers along with wholesalers, distributors and medical dealers.
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