Unlike TENS and related treatments, Galvanic uses constant direct current (DC). "DC" and "Galvanic," are often used interchangeably but it is more specifically a constant or unvarying DC that defines Galvanic.
Galvanic stimulation is a method of applying high voltage, but overall low amperage, direct current to alleviate pain, stimulate blood flow, and promote wound healing. Frequently used for injuries that are associated with bleeding or swelling, it is recognized by a number of names including HVG (High Voltage Galvanic), HVGS (High Voltage Galvanic Stimulation), HVPGS (High Voltage Pulsed Galvanic Stimulation), HVS (High Voltage Stimulation), and DC (Direct Current Stimulation).
Galvanic stimulation combines very short pulse duration and high peak voltage, yet low total current per second, to give relative comfort and avoid tissue damage while stimulating deep tissues. It is also an efficient means of exciting nerve fibers.
With its unidirectional current flow, High Voltage Galvanic's oppositely-charged electrode pads set up a reaction that calls to mind hot and cold packs for injuries. The positive pad is like ice, tending to reduce circulation to the area under the pad and decrease swelling. The negative pad is like heat, promoting increased circulation, reportedly speeding healing.