The inventions include a method of eliciting analgesia in a human subject by Transcranial Electrical Stimulation (TCES, herein “TES”). Electrodes secured to the skin of the subject's head at particular sites provide an electrical current that includes a direct current combined with rectangular AC current pulses delivered at a particular frequency of between 10 and 100 Hz. In an embodiment the total current transmitted, a sum of the DC component and a Mean Absolute Deviation (MAD) of the current pulses, has a value between 0.2 and 20 mA. The method is used to produce analgesia during perioperative period, surgery and the post-operative procedure. It can also be used for treating acute chronic pain and a wide variety of other conditions.