What is a TENS machine?
Transcutaneous electrical nerve stimulation (TENS) is a treatment that administers mild electrical currents to the skin to relieve pain. A small, lightweight, hand-held, battery-operated device produces the electrical currents and lead wires send these currents to self-adhesive electrode pads that attach to your skin.
While using a TENS machine, you'll experience a non-painful tingling or buzzing sensation, and this can help to block or suppress pain messages. Two electrode pads are usually positioned either side of the area of most intense pain. This is done so that the TENS sensation covers the painful area.
Four electrode pads can be used to treat a larger area of pain. You'll be able to control the strength, (or ‘volume’) of the current that's passed through the electrodes, with a rotary knob or dial. Some machines have larger controls that are easier to use if your hand movements are limited.
Adjust the strength of the current until the tingling sensation from TENS is strong, but not painful. You'll also be able to adjust the pattern and speed of the current, so that the TENS sensation is as comfortable as possible. Many TENS machines are digital and have helpful pre-sets to help you choose the best settings for your pain.
Side-effects and risks
TENS has minimal risks or side effects if the following precautions are followed:
- Check with your doctor or physiotherapist to make sure that using a TENS machine is a safe option for you.
- Don't use a TENS machine if you have a pacemaker or other implanted electrical device. You should check with your physiotherapist that TENS is a safe option for your pain if you have epilepsy, deep vein thrombosis (DVT), heart problems, cancer or skin that is numb, irritated or fragile.
- TENS can be used if you have these conditions, but you must seek advice from your physiotherapist or doctor first.
- Generally, you can use TENS during early pregnancy, providing it isn't used over the abdomen or lower back. Again, you must check with your physiotherapist or doctor that TENS is a safe option for your situation.
- Never place the electrodes over the front of your neck, over your eyes, directly on your head or in your mouth.
- Don't use TENS when driving, using machinery, sleeping, or in the bath/shower.
- Your skin may become slightly red and itchy when you remove the electrodes, but this should disappear quickly. It's important to monitor your skin regularly after using TENS, to ensure it remains healthy.
- If redness, itchiness and soreness persist, then contact your physiotherapist, GP or pharmacist for advice. Some people develop a more serious skin reaction to TENS and may need to temporarily stop using it to let the skin recover.
- If you intend to use TENS when flying, inform the airline first.
How TENs machines work and where you can buy them
TENS machines can be bought without a prescription at pharmacies and on the internet. Ask your doctor to refer you to a physiotherapist, so you can try it out first. Your physiotherapist can show you how to use the machine properly and will get you to try TENS for a few hours a day until you get used to it. You may be able to borrow one for a specified period of time.
After this, you'll be encouraged to use TENS regularly throughout the day, whenever you need pain relief. This is because the effects can be short-lived, although can last for hours after use.
TENS is safe, so you can use it as much as you like, although it's good practice to take regular 10-minute breaks every hour or so. Some people use TENS for more than five hours a day.
It may be worth buying a TENS machine for home use. Before purchasing one, make sure the company will give you a refund within a certain time period if you find the it doesn't help you (as long as the machine is in the same condition you bought it).
TENS machines don't vary too much in quality, so it shouldn’t matter too much if you buy a relatively simple, inexpensive device. TENS equipment is normally exempt from VAT, as long as you sign the exemption declaration form before purchasing it (usually provided by the supplier).
Before you buy a machine, ask to be shown how to use it and where to put the electrodes.
Companies selling TENS machines are listed below. Please note: inclusion on this list does not imply a recommendation by Versus Arthritis and neither is the list comprehensive. It's provided for ease of reference only.
Body Clock Health Care
108 George Lane,
London E18 1AD
Tel: 020 8532 9595
Freephone: 0500 220 0061
Performance Health UK
Nunn Brook Road
Notts NG17 2HU
Tel: 03448 730 035
Nidd Valley Medical
38 Woolmer Way
Hants GU36 9QF
Tel: 01420 487501
Boots Customer Care
PO Box 5300
Nottingham NG90 1AA
Tel: 0845 070 8090 (in-store enquiries) or 0845 609 0055 (online enquiries)