Transcutaneous Electrical Nerve Stimulation (TENS) is a very effective method of pain relief. It is used widely by health professionals for various pain symptoms from muscular and chronic pain to labour pains.

Tens machines work on the pain inhibition principles discovered by Ronald Melzack and Patrick Wall in 1965. Otherwise, known as the Melzack and Wall Pain Gate Theory.

If you put your hand onto a hot stove, you will feel pain. The heat is detected by nerves in your hand which send signals up your arm to your spinal cord. From your spinal cord, the pain signal travels up to the brain where it is perceived as pain. Pain is only perceived when the pain signal reaches the brain, not before.

The Pain-Gate theory suggests that there is a ‘gate’ in the spinal column that can be activated to block the pain signals from travelling to the brain. In effect, the pain signal is blocked at the gate. To activate the ‘gate’, there are some other types of nerve fibres that close the gate if activated. They are in effect ‘gate-keepers’. These are the nerve fibres that Tens machines have an effect on.

 Tens machines work by sending small electrical currents through the electrode pads to stimulate these ‘gate keeper’ nerves. Once stimulated, the gate keeper nerves can close the gate. Once the gate is ‘closed’, fewer pain signals can pass through the gate and therefore you feel less pain.

This is the basis of how a tens machine works and it is very effective. Pain theory has developed and evolved over time but the Melzack & Wall Pain Gate theory still forms the basis of the fundamentals of pain relief and how Tens work.  

You can also tell that this is not a cure but a symptom controller. It can be a powerful way to get effective pain relief without the use of chemical drugs. For those allergic to certain medicines or prefer to have a more natural method of pain relief, then a Tens machine can be a serious consideration.