Doctors have been using electricity to help relieve pain since the mid-1960s. This form of pain relief sends electricity directly to parts of the body. It's called transcutaneous electrical nerve stimulation, or TENS. A growing body of research says that TENS therapy may help some people in the right situation.
The main reason that people use electric nerve stimulation therapy is to ease pain. Some of the common conditions that cause pain and may be helped by TENS include arthritis, tendonitis, bursitis, surgery, migraines or other headaches, wounds, and injuries. Some experts believe electric nerve stimulation therapy has the greatest use for treating nerve pain.
Nerve stimulation therapy delivers mild electrical impulses to the body. The system is made up of a power unit, a pair of wires, and electrode pads that are placed on your skin near the place that hurts. A practitioner or patient turns on the unit, and low-voltage electrical current flows into the body.
TENS sessions usually last 5 to 15 minutes. They can be done as often as needed, depending on the case. Physical therapists and health care providers often give TENS. Doctors also can prescribe certain units to use at home. People often say they feel a mild tingling sensation or warmth during the treatments. The tingling sensation may temporarily prevent the person from being aware of pain.
Hundreds of studies have been done on electric nerve stimulation, but most have been small or weren't well designed. For this reason, some experts say TENS can give short-term relief, but long-term relief hasn't been proved.
More research is needed to know if TENS can help many kinds of acute or chronic pain. But researchers say it is better than a placebo for easing the pain of rheumatoid arthritis in the hand(s). This is according to the Cochrane Collaboration, an independent nonprofit group that does rigorous reviews of high-quality clinical trials.
Two major scientific articles have looked at the results of studies done on electric nerve stimulation for chronic low back pain and cancer pain. For the low back pain review, 4 studies met the review group's standards. But the articles had conflicting evidence, so the Cochrane Collaboration says that it's not clear whether TENS therapy can help chronic low back pain, and Medicare will not pay for TENS treatment of low back pain.
For cancer pain, the researchers said that none of the studies they looked at met their standards. They decided that more research is needed before TENS could be recommended as a treatment for cancer pain. TENS may give short-term relief for some nerve-related cancer pain, according to the American Cancer Society.
Electric nerve stimulation is generally regarded as safe. But it has risks just like any other medical procedure. For example, if the electrical current is too high or the electrodes are placed on the wrong part of the body, this can burn or irritate the skin. The "danger zones" include the brain, heart, eyes, and throat. In addition, people with heart problems, pregnancy, or implanted devices, including infusion pumps, pacemakers, and defibrillators, should not get this treatment.