Transcutaneous Electrical Nerve Stimulation (TENS) is a form of therapy that uses a low-voltage electrical current to relieve pain. TENS machines are safe and have been used by doctors and physical therapists for decades.

Modern TENS machines can be as small as a smart phone and powered by batteries. The device is connected to wires that conduct an electrical current through self-adhesive massage pads. These pads are placed on an area of pain, and a circuit of electrical impulses travel along the nerve fibers. TENS machines have different intensities or wavelength frequencies so you can adjust the flow of the electrical current. TENS is primarily used for pain relief.


TENS machines override pain receptors in the brain. A comparable way to look at this concept is by looking at phone signals. When a cell phone dials a number, it sends an air-wave path to the number dialed. The reception is either strong, weak, or not working at all. We know that with no signal, our call doesn’t go through. The same goes for pain signals.

When pain strikes, a signal travels into the spinal cord. From here the signal travels through the brain stem (medulla), and into the brain’s relay centre (thalamus), where an appropriate motor reaction is determined. These reactions could be getting away from that painful stimuli or a natural autonomic nervous system response, like rapid breathing and sweaty palms. What if we made sure that signal never got through? Electrical stimulation can block the signal so your painful call is never received.


Health professionals and pain sufferers use TENS machines to treat a number of illnesses, acute pain, and chronic pain conditions. Electrical stimulation can help treat pain related to the muscles, joints, bones, and other painful areas due to its ability to block pain signals. TENS therapy can effectively be used for the following:

Joint Pain and Arthritis

Inflammation and swelling of a joint can cause pain, limited motion, and possible erosion of the cartilage joint surface. Joint-related pain can affect any age group, but is most often seen among seniors. Combining clinical treatment, medication and TENS therapy can help relieve joint-related pain. A TENS unit can provide instant relief for inflamed joints with its convenient ability to be placed directly on an affected area. The small pads can be placed on areas prone to arthritis and joint inflammation such as the knees or hands.


Pain, fatigue, tenderness, and cognitive difficulties can all be symptoms of fibromyalgia. Placing the electrodes of a TENS unit on tender areas of the body can help block the pain signals produced by fibromyalgia. The TENS unit can also produce endorphins to mute pain signals and ease painful fibromyalgia symptoms during and after use.


Relaxing tight muscles can help stimulate the blood and nerve circulation to the head, and help reduce the pain associated with headaches. For best results, headache sufferers should place the electrodes on the back sides of the neck while lying down.

Back Pain

By relieving the pain and muscle tension, back pain sufferers often note an increase in their lower back flexibility, range of motion and strength. If you suffer from chronic back pain, we recommend massaging the painful area(s) with large electrodes, 3 to 5 times per day for at least 20 minutes each time.

Other conditions and painful symptoms TENS can be used for include:

Menstrual cramps

Knee pain

Neck pain

Foot and ankle pain

Nerve-related pain

Sports injuries

Repetitive strain injuries


How does it feel to place electrodes on your skin and send a steady electrical current along your nerves? It actually feels great! After turning on the TENS machine you will feel a tingling sensation pass through your skin.

The current produces a massaging sensation that reduces the perception of pain. As you turn up the intensity of the device you will feel the strength of the current travelling along your nerves. Some people feel the effects of pain relief in as little as 20 minutes.


An important question to ask before buying your first TENS machine is: do TENS units really work for pain relief? Studies say yes. Researchers have found that TENS machines are capable of relieving pain, reducing muscle spasms, increasing tissue oxygenation, and increasing circulation.

Dr. Michael Ho commissioned two studies to investigate the effectiveness of TENS machines. The first study measured a single TENS device’s effectiveness and the second study reviewed the effectiveness of three devices against one another. See a summarized version of both studies below.


Dr. Stuart M. McGill's Study
Dr. Stuart M. McGill conducted a study to determine the effectiveness of DR-HO’S TENS device, the Pain Therapy System. The study looked at 41 men and women from an outpatient clinic. Scientific Studies conducted by Dr. Stuart M. McGill, Ph.D. and commissioned by Dr. Michael Ho tested:

The effects of DR-HO'S muscle stimulation device on pain and muscle spasm

Changes in tissue oxygenation, as quantified by Near Infrared Spectroscopy (NIRS), while treated with DR-HO'S muscle stimulation device

Description and comparison of traditional TENS to DR-HO'S TENS device (high intensity, modulated TENS)


The above studies found that DR-HO'S TENS device can:

Significantly relieve pain

Significantly reduce muscle tension and spasms

Increase tissue oxygenation

Increase circulation


Are there side effects?  TENS machines should not create unpleasant side effects. If you experience side effects after using a TENS machine, contact your doctor to discuss the effects. There has been some evidence that indicates overusing a TENS machine can result in side effects. If you use a TENS machine for multiple hours at a time you could experience:

Muscle twitching

Muscle soreness

Tingling sensation

Skin irritation under pads 3


If you're wondering how to find the best TENS machine, consider the following variables:

TENS setting

TENS setting

Number of adhesive pads

Number of modes

Number of intensity levels

Power source

Price of unit

Ratings and reviews