--- title: "TENS Unit Safety: Who Should Not Use One and Where" description: "TENS unit safety explained: who should not use one, including pacemaker, epilepsy and pregnancy, where pads must not go, and side effects that mean stop." url: https://analgesic.multisites.ai/guides/tens-unit-safety publisher: Analgesic Healthcare phone: +1-800-749-1188 contact: https://analgesic.multisites.ai/contact --- ![A physical therapist shows a patient a back stretch](https://analgesic.multisites.ai/_astro/v3-pillar-safety.DlucyZP4_2ooQBC.avif) Patient guide # TENS unit safety: who should not use one, where pads must not go, and when to stop TENS units are not safe for everyone. The NHS says not to use TENS if you have epilepsy, have a pacemaker, or are pregnant unless your doctor or midwife tells you to. University of Iowa Health Care says not to use it with any implanted device. Never use TENS while you sleep, bathe, or drive. Updated October 26, 20269 min read2 sources ## Implanted devices University of Iowa Health Care says not to use TENS with a cardiac pacemaker, defibrillator, spinal cord stimulator, or any implanted metallic or electronic device. ## Never on these areas Both sources list the head, face, throat or neck, and broken or numb skin as places not to use TENS. ## Never during these acts Do not use TENS while sleeping, bathing, showering, or driving or using machinery. ## Stop and call Stop and call your care team for skin irritation, headache, dizziness, or nausea. ## Is a TENS unit safe? For many people, a TENS unit is safe when used as directed. It is not safe for everyone, and some uses are off limits. Check with a clinician before you start. The NHS says: “If you want to try TENS for pain relief, it’s a good idea to check with a GP or other healthcare professional first, to make sure TENS is safe for you.” The NHS is the UK national health service. Its page was last reviewed in February 2025. University of Iowa Health Care (page reviewed January 2019) asks, “Can TENS harm my body?” Its answer: “No, but it can cause some skin irritation from the patches.” It also says a TENS unit should not hurt: “Make sure you are setting it at a strong but comfortable intensity.” An electrical device can still cause problems. The same page says you can get shocked if you move or remove pads or wires without turning the unit off, if the unit gets wet, or if you touch bare wires on a damaged cord. This guide pulls together the two sources. Use it with your clinician’s and your device’s instructions, which always come first. Our [TENS units overview](https://analgesic.multisites.ai/guides/tens-units) explains the basics. ## Who should not use a TENS unit? Some people should not use TENS at all, and some should ask first. The two sources do not match exactly. Follow the stricter rule. Condition NHS University of Iowa Health Care Pacemaker Do not use Do not use (cardiac pacemaker or defibrillator) Other implanted metallic or electronic device Not listed Do not use (spinal cord stimulator, in-dwelling pumps or monitors, any implanted metallic or electronic device) Epilepsy Do not use Talk with your health care provider Pregnancy Do not use unless your doctor or midwife tells you to Talk with your health care provider Cancer Not listed Talk with your health care provider Diabetes Not listed Talk with your health care provider Cognitive impairment Not listed Talk with your health care provider Allergy to nickel or adhesives Not listed May cause skin irritation Not sure what is causing your pain See a healthcare professional before using TENS Not listed A [contraindication](https://analgesic.multisites.ai/glossary/contraindication) is a reason not to use a treatment. Each row above is one. If any row fits you, ask your clinician before you use a unit. Do not let anyone else use your unit or pads. University of Iowa Health Care says: “Just as you would not let others take a medicine that was only prescribed for you, you should not let others use your TENS unit.” For a printable list, see our [TENS safety checklist](https://analgesic.multisites.ai/guides/tens-safety-checklist). ## Can I use a TENS unit with a pacemaker or other implanted device? No. Both sources say do not use TENS with a pacemaker. The NHS lists “you have a pacemaker” under “Do not use TENS if.” University of Iowa Health Care is broader. It says: “Do not use TENS if you have: A cardiac pacemaker or defibrillator Spinal cord stimulator In-dwelling pumps or monitors Any implanted metallic or electronic device.” A [cardiac pacemaker](https://analgesic.multisites.ai/glossary/cardiac-pacemaker) is a small device that helps control your heartbeat. An implanted medical device is any device placed inside your body, such as a pacemaker, a defibrillator, or a spinal cord stimulator. University of Iowa Health Care also says that “Electronic equipment, such as EKG monitors and EKG alarms, may not work the right way when TENS is in use.” Tell any clinician who monitors you that you use TENS. If you have an implanted device, do not try TENS on your own. Ask the clinician who manages your device. Our post on [TENS units and pacemakers](https://analgesic.multisites.ai/tens-unit-and-pacemaker) covers the question in more detail. ## Can I use a TENS unit if I am pregnant? Ask your doctor or midwife first, and do not start without their advice. The NHS says not to use TENS if “you’re pregnant, unless your doctor or midwife tells you to.” University of Iowa Health Care takes a similar view. It lists pregnancy under “Talk with your health care provider if you have.” The NHS page lists labour pain in pregnancy as one use of TENS, so ask your doctor or midwife about your own case. If you are pregnant or could be, tell your clinician before you start. ## Where on the body should TENS pads never go? Never place pads on the head, face, throat, neck, mouth, or eyes, or on damaged or numb skin. Both sources give lists. University of Iowa Health Care says: “Do not use TENS on: Open wounds or rashes. Swollen, red, infected, or inflamed skin. Cancerous lesions, or close to them. Skin that does not have normal sensation (feeling). Any part of your head or face. Any part of your throat. Both sides of the chest or trunk at the same time. Directly on your backbone.” The NHS says: “Do not use TENS on irritated, broken, infected or numb areas of skin. Do not use TENS on your neck, mouth or eyes. Do not use TENS on your chest and back at the same time.” Area or skin type Do not place pads here Head or face Yes (University of Iowa Health Care) Throat Yes (University of Iowa Health Care) Neck, mouth, eyes Yes (NHS) Both sides of the chest or trunk at once Yes (University of Iowa Health Care) Chest and back at the same time Yes (NHS) Directly on the backbone Yes (University of Iowa Health Care) Open wounds, rashes Yes (both) Red, swollen, infected, inflamed skin Yes (both) Cancerous lesions or close to them Yes (University of Iowa Health Care) Numb skin Yes (both) The patches also should not touch each other or any metal object, such as a belt buckle or metal jewelry, says University of Iowa Health Care. It advises placing pads on fleshy areas, not boney sites. Our post on [where not to put TENS pads](https://analgesic.multisites.ai/where-not-to-put-tens-pads) goes deeper. For where pads can go, ask your clinician. The NHS says a clinician such as a physiotherapist can advise if you are unsure. ## When should I never use TENS? Do not use TENS while you sleep, bathe, shower, or drive. These rules appear in both sources. The NHS lists: “Do not use TENS while you sleep. Do not use TENS in the bath or shower. Do not use TENS when driving or using tools or machinery.” University of Iowa Health Care lists the same activities: “Bathing or showering, Sleeping, Driving, Using machinery.” The reasons from University of Iowa Health Care are plain: - **Sleeping:** “It is easy for the wires to get tangled or unplugged, or the patches may come off.” Not wearing it to bed “also lets your skin rest.” - **Shower or bath:** “There is a chance for electrical shock since it is an electrical device. Also, the unit is not waterproof and would be damaged.” That page also says TENS is most helpful during activities such as walking, doing chores, or exercise. Plan your TENS time for activities that are safe for you, and follow your clinician’s advice. Our post on [using TENS while sleeping](https://analgesic.multisites.ai/can-you-use-a-tens-unit-while-sleeping) covers that rule. Other protection rules from University of Iowa Health Care: 1. Turn the unit off before you put on, move, or take off the electrode pads. 2. Do not share your pads with other people. 3. Use the unit only on yourself, as instructed. 4. Keep the unit out of the reach of children. ## What side effects mean I should stop? Stop using TENS and call your clinician if you have skin irritation, headache, dizziness, or nausea. This is the University of Iowa Health Care list, word for word: “Stop using TENS and talk with your doctor or health care team if you have: Skin irritation (redness, rash, itching) Headache Dizziness Nausea (feel like you are going to throw up).” The NHS adds a skin rule: “If your skin becomes itchy, irritated or red (redness may be harder to see on brown or black skin), turn off the machine and remove the pads.” Also stop if the unit hurts. The NHS says the tingle “should not be painful.” If you feel pain, turn the unit off and call your clinician. If you feel seriously unwell at any time, get emergency help. Tell your clinician what happened before you use the unit again. Do not change or stop a medicine because of TENS. Ask your clinician. ## How do I protect my skin? Use clean, dry skin and check it after each session. [Skin irritation](https://analgesic.multisites.ai/glossary/skin-irritation) is the main reported problem. University of Iowa Health Care gives these tips: - Make sure the skin is “clean (clean off oil/lotion) and dry” so the pads make firm contact. - Wash pads gently with your fingertips under slow-running cold water if they are dirty, then air-dry them. - Put pads back on their plastic liner and in the storage bag after use. They stay sticky longer. - If pads slide because of sweat, a skin prep product may help. Ask your clinician about medical tape. - If redness, a rash, or itching appears in the first 24 hours, call your health care team and move the pads to a different site. - Do not put pads on broken or irritated skin. People allergic to nickel or adhesives “may have skin irritation with TENS,” says that page. The NHS says a healthcare professional “can also tell you about alternatives if your skin is sensitive to the sticky pads.” Check your skin after you remove the pads. Look for redness, rash, or blisters. Report anything unusual. ## Is it safe to use a TENS unit every day? Follow your clinician’s and your device’s instructions. No single safe schedule fits everyone. University of Iowa Health Care answers the question: “Do I have to use my TENS unit daily? Can I take a break?” It says: “You can take a break; 3 to 5 days off may be helpful. If your pain is at a manageable level, you may want to leave the unit off and wait to use it again when you have a flare-up. Some people use their TENS only when their pain is most severe, while others use it daily.” The same page gives a caution about long sessions. It says “Having your muscles twitch for longer than 30 minutes may cause them to get tired or sore.” It also says the stimulation may feel weaker after a few minutes, and that you can turn up the intensity so it stays “strong but comfortable.” So the safe approach is steady and simple: 1. Start with the settings your clinician gave you. 2. Check your skin before and after each use. 3. Take rest days if your clinician says to. 4. Call your clinician if your skin, your sleep, or your pain pattern changes. ## Who do I call with questions? Call your own clinician first. They know your health history, and they can tell you if TENS is safe for you. The NHS says to read the leaflet that comes with your machine for the full list of things you should not use TENS for, and to “check with a healthcare professional if you’re not sure.” For questions about getting a TENS unit, you can reach Analgesic Healthcare, Inc. (AHC) at (800) 749-1188 or through the contact page. AHC is based at 7823 N. Dale Mabry Highway in Tampa, Florida. This page is general information. It does not replace advice from your clinician. ## Next step Talk with your clinician about whether TENS is safe for you, and bring this list. Then call Analgesic Healthcare at (800) 749-1188 or use our [contact page](https://analgesic.multisites.ai/contact) with questions. ## Questions people ask ### Is a TENS unit safe? For many people it is when used as directed, but not for everyone. University of Iowa Health Care says TENS should not harm the body, but it can cause some skin irritation from the pads. Check with your clinician first. Follow your clinician's and your device's instructions. ### Can I use a TENS unit with a pacemaker? No. The NHS says not to use TENS if you have a pacemaker. University of Iowa Health Care says not to use it with a cardiac pacemaker, defibrillator, or any implanted metallic or electronic device. Ask the clinician who manages your device. ### Is a TENS unit safe in pregnancy? The NHS says not to use TENS if you are pregnant, unless your doctor or midwife tells you to. University of Iowa Health Care says to talk with your health care provider if you are pregnant. Do not start without that advice. ### Can you use a TENS unit while sleeping? No. Both the NHS and University of Iowa Health Care say not to use TENS while you sleep. University of Iowa Health Care adds that wires can tangle or unplug, and that skipping bedtime use lets your skin rest. ### Where should you not use a TENS unit? Do not place pads on open wounds or rashes, infected or inflamed skin, skin without normal feeling, the head or face, the throat, the neck, mouth or eyes, or directly on the backbone. Do not put pads on both sides of the chest at the same time. ### What are the side effects of a TENS unit? University of Iowa Health Care lists skin irritation (redness, rash, itching), headache, dizziness, and nausea as reasons to stop and talk with your care team. People allergic to nickel or adhesives may react to the pads. The NHS says to remove the pads if skin is itchy, irritated, or red. ### Is it safe to use a TENS unit every day? Follow your clinician's and your device's instructions. University of Iowa Health Care says some people use TENS daily and others only during flare-ups, and that a break of 3 to 5 days can be helpful. Stop and call your clinician if skin problems appear. ## Terms on this page - [Implanted medical device](https://analgesic.multisites.ai/glossary/implanted-medical-device) - [Cardiac pacemaker](https://analgesic.multisites.ai/glossary/cardiac-pacemaker) - [Contraindication](https://analgesic.multisites.ai/glossary/contraindication) - [Skin irritation](https://analgesic.multisites.ai/glossary/skin-irritation) - [TENS unit](https://analgesic.multisites.ai/glossary/tens-unit) ## Sources 1. [NHS: TENS (transcutaneous electrical nerve stimulation)](https://www.nhs.uk/conditions/transcutaneous-electrical-nerve-stimulation-tens/) 2. [University of Iowa Health Care: Transcutaneous electrical nerve stimulator (TENS)](https://uihc.org/health-topics/transcutaneous-electrical-nerve-stimulator-tens) Checked against the sources above on October 26, 2026. Coverage rules change, so check the linked page or your plan before you act. This page gives general information, not medical advice. Talk with your doctor or physical therapist about your own care, and follow your clinician's and your device's instructions. In an emergency, call 911. ## Keep reading - [TENS unit safety checklist: a printable list for pacemakers, pregnancy, skin and pad placementPrint this list and review it with your clinician before your first TENS session. The NHS says not to use TENS with epilepsy or a pacemaker, or in pregnancy unless your doctor or midwife says so. Do not place pads on broken skin, the head, face or throat. Do not use TENS while you sleep, bathe or drive.](https://analgesic.multisites.ai/guides/tens-safety-checklist) - [Can you use a TENS unit while sleeping? What sources sayNo. The NHS and University of Iowa Health Care both list sleeping as a time not to use a TENS unit. Iowa gives reasons: wires can tangle or unplug, pads can come off, and skin needs a rest from the pads. If pain keeps you awake, ask your clinician about other options.](https://analgesic.multisites.ai/can-you-use-a-tens-unit-while-sleeping) - [Where not to put TENS pads: a plain-language checklistHealth sources list areas to avoid with TENS pads: broken, irritated, infected or numb skin; the head, face and throat; the eyes and mouth; and both sides of the chest or trunk at once. The lists differ a little by source. Follow your clinician's and your device's instructions.](https://analgesic.multisites.ai/where-not-to-put-tens-pads) - [TENS unit and pacemaker: what to ask before you startThe NHS says do not use TENS if you have a pacemaker. University of Iowa Health Care says the same, and extends the warning to defibrillators, spinal cord stimulators, in-dwelling pumps or monitors, and any implanted metallic or electronic device. Ask your cardiologist or doctor before any TENS use.](https://analgesic.multisites.ai/tens-unit-and-pacemaker) - [TENS units: what they are, how they work, and what to ask before you startA TENS unit is a small, battery-powered device that sends mild electrical pulses through electrode pads on your skin to treat pain. The FDA classes it as a Class II device. A 2022 review found TENS may help some people, but the size of the effect is uncertain. Ask your clinician if it fits you.](https://analgesic.multisites.ai/guides/tens-units) - [Should You Do Mobility Exercises Everyday?Discover if you should do mobility exercises everyday to improve flexibility and prevent injuries. Learn expert tips for a healthier routine.](https://analgesic.multisites.ai/should-you-do-mobility-exercises-everyday) ## Questions about your unit or a bill? Call toll free. For customer care, ask for extension 508. [Call (800) 749-1188](tel:+1-800-749-1188)[Pay invoice](https://ahcpatientservices.com/)