Interferential stimulation therapy, or IFC, uses electrodes with high- and medium-frequency that alternate currents to deeply penetrate tissue. The slightly different currents are superimposed to form what is known as interference, which blocks the transmission of pain messages to the brain and can result in relief for patients. This treatment uses a much higher frequency than other electrical stimulation therapies like TENS. That means IFC penetrates the skin much more easily and reaches greater depths than other electrotherapy alternatives. IFC is frequently used to treat issues like back, shoulder and arthritis pain.