Galvanic stimulation is most useful in acute injuries associated with major tissue trauma with bleeding or swelling. In contrast to TENS and IFC units, which apply alternating current, galvanic stimulators apply direct current.
Direct current creates an electrical field over the treated area that, theoretically, changes blood flow. The positive pad behaves like ice, causing reduced circulation to the area under the pad and reduction in swelling. The negative pad behaves like heat, causing increased circulation, reportedly speeding healing.