General Adaptation Syndrome (GAS)

Authors Avatar

General Adaptation Syndrome

In the 1940s, Han Selye developed a theory which has helped us to understand why and how stress leads to illness. He tested on rats, and subjected them to a variety of stressors, such as an injection, poison or extreme temperature, and found that regardless of the nature of the stress, a similar pattern of physical responses could be found. He called this the general adaptation syndrome (GAS), and it is a model for short term effects of exposure to stressors.

The first stage is called the alarm stage; here various physical responses are engaged to deal with the stressor at hand, such as the pituitary-adrenal system and the sympathomedullary pathway(adrenaline and cortisol). Heart rate, blood pressure, breathing and energy levels increase, preparing us for fight or flight. The body is tense and ready to deal with the threat.

Join now!

The second stage is the resistance stage, if the stressor persists then our body must adapt and maintain a more stable and long-term level of arousal and coping. Our body seems to be adapting to the effects of the stressor at hand. HPA activity may stay stable or even increase, while SAM activity will decrease, reducing the initial sense of shock caused by the stressor. Although it seems the body is coping with the stressor, it has a limited amount of hormones therefore less are available for each new stressor, eventually causing the body’s resistance and immune system to be ...

This is a preview of the whole essay