What is the first stage of stress according to the provided material?

The first stage of stress is the alarm reaction. This stage is characterized by the body's immediate response to a stressor, which is part of the general adaptation syndrome proposed by Hans Selye. During the alarm reaction, the body recognizes a threat and activates the fight-or-flight response. This leads to physiological changes such as increased heart rate, elevated blood pressure, and the release of stress hormones like adrenaline and cortisol.

Recognizing this initial response is crucial for understanding how the body reacts to stress and can help medics manage stress-related situations effectively, both in themselves and in others. It sets the stage for further reactions and coping mechanisms, which are critical in the context of combat and emergency medical situations.