Transcutaneous electrical nerve stimulation (TENS) is a therapy that uses low-voltage electrical current for pain relief from several different types of illnesses and conditions. It is most often used to treat muscle, joint, or bone problems that occur with illnesses such as osteoarthritis or fibromyalgia, or for conditions such as low back pain, neck pain, tendinitis, or bursitis.
TENS is applied with a small, battery-powered device about the size of a large cell phone. Usually, two electrodes, wires that conduct electrical current, are connected from the machine to your skin. The electrodes are placed on the area of pain or at a pressure point, creating a circuit of electrical impulses that travels along nerve fibers.
When the current is delivered, many people experience less pain. There are a couple of theories as to how this works. One theory contends that the electricity from the electrodes stimulates the nerves in the affected area and sends signals to the brain that block normal pain signals. Another theory is that the electrical stimulation of the nerves may help the body to produce natural painkillers called endorphins, which may block the perception of pain.
The TENS unit can be set for different wavelength frequencies, such as a steady flow of electrical current or a burst of electrical current, and for intensity of electrical current. Your physical therapist will configure the correct settings for you.