Transcutaneous Electrical Nerve Stimulation
Other common name(s): TENS
Scientific/medical name(s): none
Transcutaneous electrical nerve stimulation (TENS) is a method of pain relief in which a special device transmits low-voltage electrical impulses through electrodes on the skin to an area of the body that is in pain.
There is some evidence that TENS may offer short-term pain relief for some people, but the long-term benefits have not been proven. More studies are needed to find out if it can help certain kinds of pain, and if it has any other role in cancer treatment.
How is it promoted for use?
Supporters claim that transcutaneous electrical nerve stimulation (TENS) is an effective method for relieving acute and chronic pain caused by surgery, childbirth, migraine headaches, tension headaches, injuries, arthritis, tendonitis, bursitis, chronic wounds, cancer, and other problems. Some say that TENS is more useful to help nerve (neuropathic) pain, which is typically tingling, numbness, or burning pain.
Some practitioners believe that TENS stimulates the production of endorphins, the body's natural painkillers. Most TENS practitioners do not claim the therapy cures the underlying causes of pain.
What does it involve?
A TENS system consists of an electrical power unit connected by wires to a pair of electrodes. The electrodes are attached to the patient's skin near the source of pain. When the unit is switched on, a mild electrical current travels through the electrodes into the body. Patients may feel tingling or warmth during treatment. A session typically lasts from five to fifteen minutes, and treatments may be applied as often as needed, depending on the severity of pain. Some practitioners refer to TENS as a sort of "electrical massage."
TENS is used widely by physical therapists and other medical practitioners but can also be performed at home by patients using a portable TENS system. There are more than a hundred types of TENS units approved for use by the U.S. Food and Drug Administration. A prescription is needed to obtain a system.
In a variation of TENS called percutaneous electrical nerve stimulation, the electrical impulses are sent through acupuncture needles (see our document, Acupuncture).
What is the history behind it?
Dr. Ronald Melzac and Dr. Patrick Wall developed the Gate Control Theory in 1965, which claims that when certain types of nerves are stimulated (by touch or electricity), a gate mechanism is closed in the spinal cord, thereby preventing the awareness of pain. After the introduction of their theory, TENS was widely used to treat pain. TENS became a relatively common therapy in the early 1970s. It is still widely used by physical therapists (physiotherapists).
What is the evidence?
Research on the effectiveness of TENS therapy for cancer pain is somewhat conflicting and is mostly limited to small clinical studies and case reports. Some cancer patients, particularly those with mild neuropathic pain (pain related to nerve tissue damage), may benefit from TENS for brief periods of time. TENS may also work better when used along with pain medicines.
Many studies of TENS have been done, but not many were well designed enough to really show that TENS might make a difference in pain relief. A 2005 review of studies that looked at the effectiveness of TENS in relieving lower back pain found very few high-quality studies. Of the two studies that met all criteria for scientifically sound research, one showed significant relief of lower back pain in the TENS group, while the other study showed no difference in pain relief between the TENS group and the control group. A 2008 review of studies that looked at TENS for pain relief in cancer patients showed that high quality studies were still lacking, and randomized controlled trials are needed to show whether or not TENS can help cancer pain.
Overall, there is limited evidence to show TENS helps chronic pain. At present, it is usually prescribed to be used with pain medicines.
Studies looking at nerve (neuropathic) pain have so far been done mainly in people with diabetes. It is unclear whether it might help people with neuropathic cancer pain.
One Turkish study looked at using TENS to improve circulation in surgical flaps after breast reconstruction, and it seemed to help, but more study is needed before this can be recommended.
Are there any possible problems or complications?
TENS is generally considered safe. However, electrical current that is too intense or that is used incorrectly can burn or irritate the skin. The electrodes should not be placed over the eyes, heart, brain, or front of the throat. People with heart problems should not use TENS. The effects of long-term use of TENS on fetuses are unknown, and pregnant women should not undergo the therapy.
People with allergies to adhesives may react to the electrode pads. Those with implanted pacemakers, defibrillators, infusion pumps, and other such devices should avoid exposure to electric current.
Relying on this treatment alone and delaying or avoiding conventional medical care for cancer may have serious health consequences.
More information from your American Cancer Society
The following information on complementary and alternative therapies may also be helpful to you. These materials may be found on our Web site (www.cancer.org) or ordered from our toll-free number (1-800-227-2345).
The ACS Operational Statement on Complementary and Alternative Methods of Cancer Management
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Note: This information may not cover all possible claims, uses, actions, precautions, side effects or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for consultation with your doctor, who is familiar with your medical situation.
Last Revised: 04/14/2011