General Adaption Syndrome

Experiencing ongoing or unavoidable stress can result in unpleasant and harmful effects, both mentally and physically. Chronic stress may cause symptoms such as upset stomach, headaches, sleep problems, and heart disease. It can also contribute to depression, anxiety, and even memory loss.

The body’s response to ongoing stress occurs in different stages known as the General Adaptation Syndrome (GAS). This syndrome represents a universal and predictable response pattern to all stressors, regardless of whether the situation is perceived as positive or negative.

Endocrinologist Hans Selye first described GAS in the 1930s and 1940s. He believed that chronic exposure to stress over time causes aging and disease. After further research, Selye found that these changes were not isolated but represented the typical response to stress and identified the three stages of GAS: alarm, resistance, and exhaustion. Understanding these stages and how they relate to one another can help individuals cope with stress.

Three Stages of General Adaption Syndrome

1. Alarm reaction stage

In this stage, your body experiences the “fight or flight” response. This natural reaction prepares you to either flee or protect yourself in dangerous situations. The sympathetic branch of the autonomic nervous system is activated and the adrenal glands secrete two hormones to stimulate your reactions to stress: epinephrine (also known as adrenalin) and norepinephrine (also known as noradrenalin).

Adrenalin mobilizes glucose and fatty acid release from fatty cells. The body is able to use both as energy to respond to stress. Adrenalin and noradrenalin also have powerful effects on the heart. Both the heart rate and stroke volume are increased, thereby increasing the body’s cardiac output. They also help to shunt blood away from the other parts of the body and thereby push more blood to the heart, brain, and muscles as the body prepares to attack or flee. At the same time, the adrenal glands also release cortisol, to help meet the body’s energy needs in times of stress.

2. Resistance stage

After the initial reaction to the stressor during the alarm reaction stage, the parasympathetic branch of the autonomic nervous system counteracts the changes that the stressful stimulus has produced, and attempts to restore a state of homeostasis, the default state in which the body functions normally.

During the resistance stage, the results of the hormonal changes which occurred in the previous stage are still apparent, including increased glucose levels in the blood and higher blood pressure, but stress hormone levels begin to return to normal, enabling the body’s focus to shift from alertness to repair.

If the resistance stage continues for too long the body will stay in a state of alertness and continue to produce the stress hormones. Signs of the resistance stage include:

• Irritability
• Frustration
• Poor concentration

3. Exhaustion stage

After an extended period of stress, the body enters this final stage of GAS. At this stage, the body has depleted its physical, emotional, and mental resources and is unable to maintain normal function. Once the body is no longer equipped to fight stress and may experience these symptoms:

• Fatigue
• Depression
• Anxiety
• Illness
• Feeling unable to cope