TENS Units: What Are They and How Do They Work?

TENS units deliver low-voltage electrical stimulation. This low electrical current stimulates nearby nerves and floods the nerve signaling system, inhibiting your body’s ability to transmit pain signals. The current may also promote the production of endorphins, which are natural pain relievers.

With the controls on your TENS unit, you can change the intensity of the electrical stimulation, the frequency of the pulses and the duration of each pulse. For each of these, begin on the lower end of the scale and work your way up until you find appropriate relief.

TENS units can potentially help manage pain for a wide range of conditions. If prescription painkillers aren’t working for you, or you want to decrease or avoid using these medications, consult with your physician to see if TENS units are a good option for you. TENS units are also great at helping with workout recovery.

To be clear: TENS units are not designed to address the underlying causes of pain; they are only decreasing the experience of discomfort. So, if you have chronic pain, you should always visit a healthcare professional to identify underlying issues and find out whether there are ways to treat those problems.

TENS units can be helpful in relieving many types of pain, including:

• Chronic back pain, including sciatica
• Headaches and migraines
• Neck pain, shoulder pain and muscle stiffness
• Arthritis and other chronic joint pain, such as bursitis
• Pain from injuries like pulled muscles or sprains
• Postoperative pain
• Menstrual cramps and endometriosis
• Fibromyalgia
• Neuropathy caused by diabetes
• Peripheral artery disease (pain resulting from hardening of the arteries)
• Tendinitis (swelling of the tendons)

As you can see, the benefits of using a TENS unit to relieve pain make it a popular choice for a variety of ailments. Whatever you choose to address with your TENS unit, you should always clear that usage with a healthcare professional.

There are areas of the body where you should not use TENS units. Certain health conditions can further eliminate certain areas and options, including pregnancy, deep vein thrombosis, heart disease and epilepsy.See Disclosure ²

TENS units are portable and lightweight, so they're easy to carry around, but some are smaller than others. So, it’s important to decide how you would like to use your unit and let that inform your decision about size.

Always choose a unit with an interface that you find easy to use. Some TENS models must connect to a smartphone in order to operate. So, make sure you’re comfortable using any necessary technology.

You should also consider whether you want to buy a unit designed to address a specific problem. For instance, some TENS units come with a knee sleeve specifically meant to work on knee pain. Whatever unit you choose, make sure to have replacement sticky pads available as needed (the shape of the pads may vary depending on the model).

1. Lillis, C. & Minnis, G. “What Is a TENS Unit and Does It Work?” Medical News Today, Healthline Media. November 9, 2018. https://www.medicalnewstoday.com/articles/323632.

1. Teoli, D. & An, J. “Transcutaneous Electrical Nerve Stimulation.” StatPearls Publishing. January 22, 2023. https://www.ncbi.nlm.nih.gov/books/NBK537188/.