In the physical therapy setting, some procedures include the use of electrical current to stimulate a therapeutic effect on the body. When applied to tissue, electric currents create thermal, physiologic, and chemical responses. The currents also alter pain impulses. Interferential stimulation is the most commonly used form of electrical stimulation used in the physical therapy setting. Two channels of electrical stimulation create a third current that penetrates the affected tissues with little resistance. This stimulation helps control pain and muscle contractions. Interferential stimulation also reduces edema, swelling caused by fluid in the body’s tissues.