Electrotherapy What is electrotherapy? Electricity has been used to treat pain for over 100 years. Early proponents of electricity were labeled as charlatans, but recent scientific studies have proven that electricity can reduce both acute and chronic pain. The exact mechanism of electrical stimulation’s beneficial effect remains controversial. Electrical stimulation may directly block transmission of pain signals along nerves. In addition, electrical stimulation has been shown to promote the release of endorphins, which are natural painkillers produced by the body. Several different electrical stimulation devices exist, each producing different frequencies, waveforms, and effects. Electrical modalities include Transcutaneous Electrical Nerve Stimulation (TENS) (the most commonly used) Interferential Current (IFC) Galvanic Stimulation (GS) Common characteristics of electrotherapy stimulation TENS, IFC, and GS all apply electrical stimulation to nerves and muscles via adhesive pads placed on the skin. These devices are powered by batteries, and some units have an adapter that allows powering from an outlet. Side effects are rare, but include allergic skin irritation under the adhesive pads and transient pain from the electrical charge. Placing the pads over the heart or over pacemaker leads could conceivably cause cardiac arrhythmia; placing them over the throat could conceivably cause low blood pressure; and placing them over a pregnant uterus could conceivably cause fetal damage. Because of these risks, electrical stimulation over these areas should be avoided. Electrical stimulation should also not be applied over malignancies or infected areas.