If you have ever gone to physical therapy, you have more than likely been exposed to what a TENS machine is. A TENS machine is a medical device that aims to reduce the sensation of pain through the utilization of sending low levels of electricity across the skin. 

TENS units are now becoming a more mainstream method of achieving pain relief with at-home options becoming more widely available. To get the maximum pain relief possible from a TENS unit, it is important to know how it works, how to properly use it, what pain it can help with, as well as its limitations. Having a solid understanding of these aspects will enable you to achieve the best results possible with a TENS unit at home. 

What is a TENS Unit?

TENS stands for Transcutaneous Electrical Nerve Stimulation. In layman’s terms, it is a device that stimulates nerves through the application of electricity to the surface of the skin. The device consists of a device with 2 or more electrical leads that have adhesive to stick to the skin. Some units are battery operated while others need to be plugged into an outlet.

Another commonly confused device that resembles a TENS unit is an Electrical Muscle Stimulator (EMS). Both look relatively the same and consist of leads placed on the body. The main difference between the two devices is the target of the electrical pulses. 

For a TENS this is the nerves while for EMS it is targeting the contraction of muscle cells. TENS units are utilized for the primary purpose of pain relief while the primary purpose of the EMS device is to stimulate muscles for recovery, training, and more. 

How Does a TENS Unit Work?

A TENS unit as described above is a device that sends pulses of electricity across the surface of the skin to stimulate nerves. Two main questions need to be answered to understand how a TENS unit works: how does electricity get sent across the skin and how does it provide pain relief?

Electrical devices work through the ability to pass electrons through a circuit. A circuit needs to be closed or in other words, there can be no breaks in a circuit otherwise electrons will not flow and the device will not work. 

Relating this to a TENS unit, the two electrical leads can be thought of as an open circuit. Only when two leads are placed on the body will the unit work. As described above, this is because the leads still have an open circuit, and as such electricity will not flow. 

When you place the two leads on the skin it becomes a closed circuit with the part of your body between the leads becoming a part of the circuit. The electrons readily flow from one electrical lead to another through the skin. Your skin is able to conduct electricity because of the electrolytes present in the body. If you were to place the two leads on a non-conductive material like a piece of rubber, the unit would not work because electrons could not flow from one lead to another.

The TENS unit acts to relieve pain through two proposed mechanisms. The first of which is through manipulating what is known as the Gate Control Theory of Pain. The theory proposes that the brain is not capable of receiving numerous signals from a given location at once. Through the activation of peripheral touch nerves through the TENS unit, the pain signals are essentially drowned out resulting in immediate pain relief. Depending on the severity of the pain determines the amount of electrical noise the TENS unit needs to provide. This mechanism seems to explain the immediate pain relief offered by a TENS unit. 

The other proposed mechanism to explain the pain relief of a TENS unit is the release of natural endorphins. The mechanism proposes that the electrical stimulation is able to stimulate the release of endorphins which are the body’s natural pain killers. This explains the reason that some people experience pain relief well after they take off the machine and throughout the day. Endorphins have lasting impacts on the body and the release of endorphins can have drastic impacts on the perception of pain.

How Do I Use a TENS Unit?

The first step to using a TENS machine is to look at the warnings of the unit. TENS units cannot be utilized by people with certain conditions and checking you do not have any of these conditions will ensure you are safe to use the TENS machine. 

When you have checked to ensure you are clear of the conditions, you can begin the steps of properly applying the leads. First, you will want to determine the area causing pain. With the area identified you will want to clean the skin around the area causing pain. Once clean you should apply the leads across the area ensuring the unit is in the off position. Proper placement can be checked by looking to see if the painful area is in the middle of the two leads and an imaginary straight line from lead to lead can be made. 

Once the leads are secure on the surface of the skin, you can turn the unit on to the softest setting. Gradually increase the intensity of the unit until the pulses become strong but not painful. Slight muscle twitching may occur but this is normal. Once the desired intensity is dialed in you can go about your day carrying out daily activities while the TENS unit goes to work. Doing tasks and moving the area during TENS stimulation can help in the effectiveness of the treatment. 

To remove the TENS unit you will want to ensure the device is in the off position. Unplug the leads from the device and then remove the skin contacts. Place the covers back on the contacts and store the unit away.

With these simple steps, you can be on your way to pain relief all from the comforts of your own home.

Does a TENS Unit Hurt?

A common question is whether or not a TENS unit session is painful. While the thought of sending electricity through your body may sound painful, for the vast majority of people, the TENS unit stimulation is not felt as pain. Many people describe the sensation as a tingle. While the TENS unit is not typically painful, having the intensity set too high can lead to discomfort. 

If you do feel pain, develop a headache, or become dizzy, stop using the TENS unit and talk to your healthcare provider.

What Are the Limitations of a TENS Unit for Pain Relief?

The largest limitations to the TENS unit are that people with pacemakers cannot utilize the TENS unit and the unit cannot be used to alleviate pains located on the head, face, throat, or on the spine. The electrical pulse of the TENS unit can also interfere with a pacemaker or other vital muscles and is why it cannot be utilized in this manner.

What Are Alternative Ways of Achieving Pain Relief?

Alternatives to a TENS unit treatment to temporarily relieve joint pain, back pain, and muscle pain includes the following:

Trolamine Salicylate Creams – Trolamine Salicylate is a pain reliever that is used in Hempvana’s pain relief cream. Trolamine Salicylate in addition to other ingredients like hemp seed oil, aloe, and turmeric can provide fast-acting targeted temporary relief that can also help with skin irritation. In fact, Hempvana Gold Pain Relief Cream can be applied after a TENS unit session to minimize skin irritation from the leads while also providing further soothing. 

Menthol – Menthol can be used as a topical treatment that utilizes the similar methodology the TENS unit uses. A product like Hempvana’s Cold as Ice Gel Patch can temporarily decrease the sensation of pain by activating the cold sensing receptors to provide neural signaling noise to drown out the signals of pain sent to the brain. Just like the cream, the patch can be applied after a TENS treatment to provide even further soothing than the TENS could accomplish on its own.


To summarize, a TENS unit stands for a Transcutaneous Electrical Nerve Stimulation unit. The system works by stimulating nerves across the skin to drown out the sensation of pain and to potentially release natural painkillers in the body. Knowing the underlying science behind how these units work, as well as the knowledge of how to properly use them will give you the best chase at getting the maximum pain relief possible with a TENS unit. 

For supplemental pain relief between sessions or instead of if you do not qualify to utilize a TENS unit, Hempvana has you covered with a wide variety of pain relief options