Explanation of Pain
Pain is a warning system and the body’s method of telling us that something is wrong. Pain is important; without it abnormal conditions may go undetected, causing damage or injury to vital parts of our bodies. Even though pain is a necessary warning signal of trauma or malfunction in the body, nature may have gone too far in its design.
Aside from its value in diagnosis, long-lasting persistent pain serves no useful purpose. Pain does not begin until coded message travels to the brain where it is decoded, analyzed, and then reacted to. The pain message travels from the injured area along the small nerves leading to the spinal cord. Here the message is switched to different nerves that travel up the spinal cord to the brain. The pain message is then interpreted, referred back and the pain is felt
Explanation of TENS
Transcutaneous Electrical Nerve Stimulation (TENS) is a non- invasive, drug free method of controlling pain. TENS uses tiny electrical impulses sent through the skin to nerves to modify your pain perception. TENS does not cure any physiological problem; it only helps control the pain. TENS does not work for everyone; however, in most patients it is effective in reducing or eliminating the pain, allowing for a return to normal activity.
How do TENS machines work?
There is nothing “magic” about Transcutaneous Electrical Nerve Stimulations (TENS). TENS is intended to be used to relieve pain. The TENS unit sends comfortable impulses through the skin that stimulate the nerve (or nerves) in the treatment area. In many cases, this stimulation will greatly reduce or eliminate the pain sensation the patient feels.
Pain relief varies by individual patients, mode selected for therapy, and the type of pain. In many patients, the reduction or elimination of pain lasts longer than the actual period of stimulation (sometimes as much as three to four times longer). In others, pain is only modified while stimulation actually occurs. You may discuss this with your physician or therapist.
How effective are TENS machines?
Research trials looking at the effectiveness of TENS machines have so far
been inconclusive. Further large studies are needed to clarify the precise
role and effect of using TENS.
However, TENS machines have proved to
be a popular form of pain relief with some people. As with many forms of
treatment, the effect can vary from individual to individual, even with the
How are TENS machines used, and by whom?
It is best to use a TENS machine only on the advice of a doctor or other
health professional. They are not suitable for all types of pain or all
A TENS machine is personally controlled by the user. This
means its settings can be adjusted, without having to visit a medical
professional. Typically, a machine would be used for 15-20 minutes per
session, several times per day. See below for specific instructions.
TENS machines are most commonly used for people with musculoskeletal pain,
such as chronic (long-term) back pain or knee joint arthritis. They are also
often used for pain relief in the early stages of labour, particularly whilst a
pregnant woman remains at home.
Other less common uses include
migraine headaches, period pains, sports injuries and sometimes (quite
rarely) non-painful conditions such as tiredness, insomnia or dementia.
TENS machines can be used alone for pain relief, or be combined with
other treatments. The use of a TENS machine might allow reduction of the
amount of painkilling medicines you take. Although you might need to try a
few settings on your TENS machine before finding the best one for you,
there are no real side-effects from using a TENS machine.
A TENS machine might be worth a trial, particularly if conventional pain relief methods have been tried and exhausted. Importantly, TENS machines can
be expensive. It is probably best if you hire or borrow one first, to try it out.
If you plan to try TENS in labour, your midwife or local National Childbirth
Trust (NCT) branch should be able to locate one to rent. If you are new to
using a TENS machine, take things slowly, even if you are finding it useful.
Don’t try to do too much too soon (as you may hurt yourself and make the
pain worse) and don’t stop all of your normal painkilling medication too
quickly. If you are on either a lot of strong painkillers or a number of
different ones, it might be worth consulting your doctor for advice on how to
reduce them safely, with minimal side-effects.
Can TENS machines be used by everybody?
TENS machines tend to be mainly used to help reduce pain associated with problems in muscles, joints and nerves (so-called musculoskeletal pain) rather than abdominal, chest or head pains. Unlike a lot of medication there are
virtually no side-effects when using a TENS machine.
People with the following must not use a TENS machine:
- When the cause of the pain is not known or is not diagnosed.
- Pregnancy (unless specifically medically advised – or in labour).
- Epilepsy or certain types of heart disease
- ENS Stimulator
- 9 Volt Alkaline Battery (6LR61)
- 2 x Patient Cables
- 4 Self-Adhesive Electrodes
- 1 x Carry Case
- 1 x User Manual
1 Year Parts Warranty
Instructions for using a TENS machine?
There are various types and brands of machine. Always follow the manufacturer’s instructions supplied with your machine.
Cautions when using a TENS machine
- Do not place electrode pads on broken or damaged skin.
- Do not place electrode pads over the front or side of the neck, close to
eyes or in the mouth.
- Do not use over areas of reduced sensation.
- Do not use near water such as in the bath or shower.
- Do not use when driving or operating machinery.