A TENS machine is a transcutaneous electrical nerve stimulation machine, which is usually just called TENS. This machine sends a low level of electricity through a person's skin. Its purpose is to block pain signals and help the user control and withstand pain. Scientific evidence also suggest that the electrical current produced by these machines increases endorphin levels, further decreasing pain since endorphins are a natural type of pain killer the brain produces on its own.
Interestingly, pain control via electrical stimulation is not a new concept. Electrical current was used to handle pain as far back as 63 CE in Greece. Historical documents reveal that patients could receive some pain relief by standing on electrical fish. In more modern times, many crude electrical devices were tested and used in pain treatment, with varying levels of success. The year 1974 saw the patenting of the first TENS machine that a patient could wear and operate.
The idea of sending electrical current through the body may sound painful and even dangerous. However, TENS machines usually produce only mild, low-level currents and are considered safe for the body. These machines are used for treating pain that is temporary as well as chronic pain and discomfort. However, some people question their effectiveness in conditions that have painful symptoms that last for longer periods of time.
In order to deliver the stimulation necessary for pain relief, a TENS machine must be connected to the patient’s skin via electrodes. TENS units are usually operated by battery power and are portable, allowing users to move around and accomplish other tasks while using them. There are units designed for use by patients while others are intended to be used by medical professionals. The TENS units intended for medical-setting use are generally more complex and allow for more frequency- and pulse-setting variations.
TENS machines may be used to help control muscular, joint, and nerve pain, but they are unlikely to be as helpful for pains in the abdomen and chest. Often, they are used when pain medication is undesirable for some reason, but there are some people who should avoid them. A person who is unsure of the cause of his pain should not use a TENS machine to treat it. Also, those with pacemakers, epilepsy, and some heart conditions should avoid this form of treatment. Likewise, pregnant women are usually advised to select an alternate method of pain control.