What's A TENS Machine and Why Use One?

The abbreviation TENS stands for ‘Transcutaneous electrical nerve stimulation’ and it indicates a pain relief method with the use of a mild electrical current. The ‘transcutaneous’ is a fancy science word for “across the skin”, which means that the TENS machine stimulates the nerves in your body by channeling electrical current through your skin.

A TENS machine is a small device that operates on batteries and is worn on the body – it has wires (electrodes) which are connected to sticky pads. The pads are attached directly on the skin, on the area affected with pain. When you turn the machine on, it sends mild electrical impulses which you end up feeling as a tingling sensation.

Some people use the TENS machine as an alternative option to painkillers, especially because it can also stimulate the body’s production of endorphins, hormones which are responsible of being the natural painkillers of the body. Through the production of electrical impulses, the TENS machine reduces the pain signals that go to the spinal cord and the brain, which can help relax the muscles and ease the pain.

The TENS machine is considered as an effective means for pain-relief, though it shouldn’t be used for every type of pain. One of the advantages is that it usually doesn’t cause side effects and is well tolerated by the body.

What Exactly is the TENS Machine Used for?

The TENS machine is a device used as a pain reliever for a variety of conditions that cause musculoskeletal pain or muscle spasms, as well as other types of pain in the body, such as:

Knee pain
Arthritis
Neck pain
Back pain
Pelvic pain caused by endometriosis (displacement of the uterus tissue)
Period pain
Sports injuries

TENS can also sometimes be used to treat pain during labor.

How Does a TENS Machine Work?

As we said earlier, the TENS machine works by sending a low electrical current through your skin to the affected area.

The TENS machine can work in two ways, set on a high and low pulse rate.

The regular method of use of the machine is when it set on a high pulse rate (which goes between 90-130 Hz). In this rate, the machine generates electrical impulses that interfere with pain messages which are sent to the brain, and also block them. The way this is achieved is by following the so-called ‘gate control’ pain theory. According to this theory, there is a certain type of gate mechanism present in the brain, as well as the nerves of the spinal cord (the central nervous system). When this gate is open, pain messages manage to get through to the brain, resulting in sensations of pain. But, when the gate is closed, the pain messages are blocked and we don’t have sensations of pain, meaning we don’t feel pain. The TENS machines are supposed to stimulate certain nerves that don’t carry pain messages and thus close the gate. This means that the brain gets busy with sorting out the fast-pacing messages from the TENS machine, as opposed to the slower, pain-carrying signals the body receives from somewhere else. Think of it this way: when you injure yourself, sometimes it helps to temporarily rub the hurt area in order to reduce the pain.
The other method of use is when it is set on a low pulse rate (ranging between 2-5 Hz). With this method, the machine stimulates the body by making it produce its own pain-reducing hormones (endorphins) which actually act like blocking agents to the pain signals.

How to Use the TENS Machine

The good thing about TENS machines is that they are small and weigh very little, which means you can use them in a variety of places, during working hours, or while on the move. They can fit into a pocket, can be attached to a belt or just held in the hand. The machine can be used throughout the whole day for as long as you like, although it’s not advisable to use it while driving, operating machinery, and especially not while in the bath or shower.

The following information serves as a general guide on the ways of using a TENS machine, but shouldn’t be a replacement for more specific instructions. Always read the instructions as proposed by the manufacturer of the device.

Instructions for Using a TENS Machine

First of all you have to make sure the machine is switched off before you proceed attaching the sticky pads on your body. You should position the pads on each side of the affected area, with at least 2.5 cm (1 inch) in between.

It’s very important to note never to place the pads over areas such as:

The temples
The mouth or eyes
The front or the sides of the neck
The chest and the upper back at the same time
When skin is irritated, broken or infected
On areas with swollen, enlarged veins (so-called ‘varicose veins’)
Areas that are numb

Turning the Machine 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. You can also first test the machine by holding the sticky pads between your fingers, then turn it on and wait for the tingling sensation.

As we mentioned before, the skin where the pads are attached must be dry, clean, and without any irritation or cuts.

Use the machine dial that allows you to control the strength of the electrical impulses. It’s recommended that you start with a low setting at first and then increase it gradually until you reach a phase where the sensations are stronger but still comfortable. At one point you may reach the so accommodation phase, which means the sensation might start to drop slightly. When this happens, increase it again slightly and leave it in use. Reduce the pulse rate if the tingling sensation starts to feel uncomfortable or painful – this might cause over-stimulation of the area and worsen the pain. Also, be vary of muscle contractions – you shouldn’t feel one while using the machine.

When you finish a session, turn off the machine and remove the electrodes from your skin.

What to Consider Before Using the TENS Machine

Always advise with your doctor or healthcare professional before deciding to use the TENS machine. These devices are not necessarily suitable for all pain-inducing conditions. In some cases, it may be better to try other treatments and painkillers first or use them in parallel to using the machine.

What are the Side Effects of Using the TENS Machine?

The TENS machine doesn’t cause any side-effects in most people that use it and it is considered a safe treatment of muscle pain.

The pads might cause an allergic reaction in some people, making the area of the skin where they are placed red and irritated, but this can be easily solved with acquiring special pads for people with allergies.

You should be careful when using the machine and should definitely seek medical advice if you have the following conditions:

You’re either pregnant or there is a chance of being pregnant – TENS is not recommended to be used early on in pregnancy
You have a pacemaker or some other type of electrical or metal implant in your body
You have epilepsy or have a heart condition

Final Note

The TENS machines can be used alone to treat pain affected areas and can also be combined with other treatments.

A TENS machine is worth a shot, especially if more conventional methods have proved unsuccessful so far.

Unfortunately, these machines can be a bit expensive. That’s why it can be useful to first borrow or hire one and try it out to see if it has the desired effect on you.

If you’re new to using the machine, make sure to take it easy, even if you see immediate results of pain-relief. Don’t overdo it, because it may worsen your pain condition. If you take painkillers along with the machine, don’t stop them right away, especially not on your own hand. Always consult with your physician for advice before making any final decisions.