Transcutaneous electrical nerve stimulation (TENS) is a method of providing pain relief. As the name suggests, it involves the application of electrical current to the affected area. This is achieved via a number of electrodes that can be fixed to the skin.
How does TENS work
TENS relieves pain mainly by stimulating the pain gate mechanism. When tissue becomes damaged, the pain nerve fibres in the area become irritated and increasingly sensitive which leads to a heightened perception of pain in that area. However, in that region there are also a number of mechanoreceptors which respond to touch. Stimulation of these nerve fibres can override the pain impulses from that area- this is known as the pain gate mechanism. These mechanoreceptors can stimulated by an electrical current at certain frequency (usually 90-130 Hz) as provided by the TENS machine which in turn causes a pain relieving effect.
The use of TENS is an extremely popular method of pain relief. It is relatively cheap, easy to use and the side effects are minimal when compared to some oral pain killers. It is thought that TENS can provide pain relief in the region of almost 70% of cases suffering from an acute injury.