Electrosurgical units (ESU) use a high-frequency electrical current to cut tissue and control bleeding by causing coagulation. Tissue resistance to the high-density current causes a heating effect which results in tissue destruction. Electrical current is delivered and received through cables and electrodes.

Electrosurgery is a technique often used in surgery to control bleeding and to rapidly dissect soft tissue in surgery. The electrical resistance of these soft tissues to an electromagnetic current generates heat. The endpoints of electrosurgery vary based on the waveform, power used, and surgical technique.