Life is made up of a variety of experiences, ranging from happy and exciting to sad or frightening. These less positive experiences are considered a stress. The normal response to stress to feel it, and have an appropriate physiological response to it at the time. Over time this stress response lessens and eventually disappears – this is called extinction.
Sometimes when we think back on these experiences they may trigger a physiological reaction in us . We may experience the original emotion, or we may have a general sense of feeling upset or anxious, or something more subtle