"Selye proposed a three-stage pattern of response to stress that he called the General Adaptation Syndrome (GAS). When the organism first encountered stress in the form of novelty or threat, it responded with an alarm reaction. This was followed by a recovery or resistance stage during which the organism repaired itself and stored energy. If the stress-causing events continued, exhaustion set in. This third stage became popularly known as burn-out. Classic symptoms of burn-out include loss of drive, emotional flatness, and, in humans, dulling of responsiveness to the needs of others. In 1934, Hans Selye at McGill University discovered a new type of hormone. He gave rats daily injections of ovarian extract and found that the rats had enlarged adrenals, shrunken spleens, thymus, and lymph nodes, and intestinal ulcers. In 1936, Selye defined these symptoms as the General Adaptation Syndrome, consisting of the alarm, resistance, and exhaustion stages. The alarm stage is similar to the fight-to-flight response, and the body mobilizes resources to react to the incoming noxious agent. Resistance forces build up when the noxious challenge is detected as continuing. The exhaustion stage can cause death if the body is unable to overcome the threat."