Stress and the mind
The stress reaction starts in the area of your brain called the amygdala, which sends signals to other areas of the brain to activate the sympathetic nervous system.
This system triggers epinephrine (adrenaline) and cortisol – the stress hormone – to flood through your body within seconds.
Your senses, especially the eyes and ears, become sharper. Meanwhile, pain perception is reduced. More blood rushes to your brain so that you become more alert and ready to respond.