A Guide Understanding the TENS Machine Easily, Effortlessly, and Efficiently

How does a Tens Unit Work?

A tens unit, short for transcutaneous electrical nerve stimulation, uses low voltage electric current to relieve pain. Portable tens unit reviews say that it delivers a tingling sensation. A tens unit is a small, portable device that can be worn and used for pain relief for up to 12 hours. Tens units have adjustable settings to control the intensity of stimulation by controlling the voltage. Electrodes are then placed in specific, painful places on the user’s body. A tens pain management device works to non-invasively and non-addictingly work to relieve pain. 

Using Tens Unit

How does a tens unit work to relieve pain?

Tens machines are a kind of pain management device. The current created by the placement of electrodes travels through them and into the skin, stimulating specific nerve pathways under the skin to produce a tingling or even massage-like sensation. 

Machine Parameters

  • The intensity of pulses varies between 0 - 80 mA. Some can go up to 100, but this is still considered a relatively small current. This small current is not a detriment because the sensory nerves are so sensitive and pain relief can still be achieved. These nerves have low thresholds and are quite easy to “excite” and will respond well to any electrical change. 
  • The tens machine delivers subtle ‘pulses’ of electrical energy. The rate of these pulses are usually, roughly, 1-2 pulses per second. To ensure pain relief and maximum effect, pulses should be in the range of 2-150 pulses per second 
  • The pulses delivered by TENS stimulators can vary between models and manufacturers 
  • Due to the biphasic nature of the pulse output, there is usually no “DC component”. What does this mean? Well, boiled down, minimized skin irritations and issues

Mechanism of Action 

  • The type of stimulation delivered by the TENS unit aims to stimulate sensory nerves. Ultimately the tens machine works to activate certainc natural pain relief mechanisms. The two main pain relief mechanisms can be activated are the Pain Gate Mechanism and the Endogenous Opioid System 
  • The Pain Gate Mechanism involves an “activation” of sensory fibers. This activation reduces the transmission of the pain stimuli from ‘c’ fibers through the spinal cord. The A beta fibers respond well to this stimulation, thus alleviating pain 
  • The Opioid mechanisms provide pain relief through the act of the release of an endogenous opiate (also known as encephalin) in the spinal cord that aims to reduce the activation of painful sensory pathways. 
  • It should be noted that for these two mechanisms of action that there is no single, perfect, consistent, or fool-proof frequency that works best for everybody. People that use the tens machine are encouraged to explore different settings to see what works best for them. 

How many volts in a tens machine?

  • The regular voltage of a tens machine has about a 9 volt battery (though it can go up a little or down a little) 
  • Keep in mind that voltages higher than 40-50 can be dangerous if not used carefully and with direction from a medical professional 

Using a TENS machine

Using a TENS machine is easy and accessible for everyone! 

  • They are portable, small, and work well on all different parts of the body
  • The tens machine is a non invasive way to treat pain
  • Tens applications are made using self adhesive, pre-gelled electrodes which work to reduce infection risk, make the application process easy, and provide a lower cost 

All you need to do then is make sure the skin where the electrode pads are going to be applied is clean and dry. You should always make sure are no cuts, grazes, or skin irritation whatsoever. Then, set the pulse rate to the required setting (usually starting with about 100 Hz). At the end of the session, turn the machine off and disconnect the electrodes from the machine. A portable, rechargeable tens unit works wonders for pain relief accessibility and arability. 

A medical tens unit works by

  • TENS is a method of electrical stimulation that provides a degree of pain relief by exciting sensory nerves and thereby stimulating either the pain gate mechanism and/or the opioid system.  
  • The type of stimulation from the TENS unit aims to stimulate the sensory nerves, and by so doing, activate specific natural pain relief mechanisms. 

Digital Tens Machine

Digital TENS machines are becoming more widely available and extra features like,

  • Automated frequency sweeps
  • Complex stimulation patterns
  • Often equipped with dual channels
  • More options for customization

Best Tens Units for Home Use


Under $200

Healthmate Forever


TENS and EMS/PMS Support - Dual Channel & 12 Modes


Under $100


TENS + EMS Combo

All in One Simple to Use Device.


Under $50


Tens 7000

Popular tens unit with dual channel and 5 modes


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