The high-frequency, high-voltage current generated by a high-frequency scalpel passes through high-impedance tissues, generating heat in the tissues and causing them to vaporize or coagulate. During electrosurgical use, the resistance varies from 100 ohms to 2000 ohms. As the tissue coagulates, the water in the cells vaporizes, drying out the tissue and causing the resistance to increase and eventually the current stops completely.