Aperson is in the of the general adaptation syndrome when the body becomes more vulnerable to other stressors. for example, when the body is mobilized to deal with a heat wave or pain from a broken leg, it is easier to be annoyed by minor frustrations.

There are three stages of general adaptation namely: alarm reaction, resistance and exhaustion. In the alarm reaction stage, when the stressor is detected, a signal is sent to the hypothalamus which enables the release of hormones called glucocorticoids which then releases adrenaline and cortisol. Adrenaline boost the body's energy while the cortisol is the stress hormone. In this stage, the person is prepared to respond to the stressor also called as "fight or flight". In the resistance stage, the body tries to counteract the changes that happened during the alarm reaction stage. It is govern by parasympathetic branch of ANS wherein it tries to return the body to normal by reducing the amount of cortisol produced. When the stressor comes to an end, the body returns to normal but if it remains, the body will stay alert until the body finally goes to the exhaustion stage. In this stage, the body has depleted its energy resources and could no longer equipped to fight the stress. It is the stage wherein the body is vulnerable to other stressors thus increasing the risk of developing stress-related health conditions.

Cells of an organism tell each other when predators are near.