The use of electrical current produced by a device to stimulate nerves therapeutically is the definition of a transcutaneous electrical nerve stimulation device. These therapeutic devices are most commonly used in hospitals and physical therapy offices to help patients get relief from chronic and even acute pain. TENS units were first used back long ago for pain control.It was reported when the thought of controlling pain came about that pain was relived by standing on an electrical fish on a beach. Numerous electrostatic devices were used to relieve pain from headaches as well as other severe pain. The first patented portable device arrived in 1974, initially used more so for pain tolerance tests in people suffering from various forms of pain.More patients found relief from pain when using these devices, although they were intended only Harmonic Reducer Manufacturers for testing pain tolerance. More and more devices were produced and now therapists and doctors everywhere are using the trans-cutaneous electrical nerve stimulation method to help relieve the pain of their patients.These devices are not only used in the offices of physical therapists and doctors but also in the homes of people with acute and chronic pains of all sorts. With portable TENS devices people can get pain relief wherever whenever. For some electrical nerve stimulation does not relieve pain, it just makes it worse. Everyone is different and we all have different pain tolerances, TENS units may work for some and may not work for others. There are doctors everywhere who can talk with you about these devices and whether they would benefit you or not.TENS units are non-invasive and safe nerve stimulation devices intended to reduce or even relieve pain, both chronic and acute. These devices can cause cell death with prolonged use so it is recommended that patients only use them for short periods of time. The amount of cell death that occurs with the use of these devices is extremely minimal, but can increase with long time use.Never should a unit be placed directly over an artificial cardiac pacemaker or over the spinal column. Use over the eyes is not recommended due to increasing intro-vascular pressure, or on the front of the neck due to acute hypo-tension. TENS units should never be placed on broken skin or wounds, though they may relieve pain around the wound.Effects produced by these nerve stimulating devices are due to the high and low frequencies that produce activation of opioid receptors in the central nervous system. TENS units also release and activate serotonin and serotonin receptors in the spinal cord. This is how these devices are able to relieve pain in most patients.Using a TENS unit can be helpful to someone with a lot of pain, but it can also make their pain worse. Only a doctor can help you figure out if this type of treatment will work for you and your pain. Doing research can help you better understand the TENS unit and how it could help you.