Anxiety is part of a primitive human response known as ‘Flight or fight’ which is meant to help us deal with sudden and unexpected dangers. 

It evolved millions of years ago when early humans often met life-threatening situations. When suddenly faced with a saber-toothed tiger, we needed to react quickly by either running away or fighting.

We no longer need to deal with the threat posed by wild animals but we still experience this same response today. Have you ever been woken in the night by a noise and sat bolt upright, fully alert with your heart pounding? If you’d woken up feeling relaxed, you would not have been ready to respond to the danger of an intruder in your house.

The threat response is triggered as soon as the brain becomes aware of a possible danger. Hormones, called adrenaline and cortisol, are quickly released to help the body prepare for running away or fighting. These changes include:

  • our breathing getting quicker and heavier to take in extra oxygen
  • the heart beating faster to send blood to the leg muscles
  • muscles all over the body tensing and legs shaking to get ready to run
  • feeling ‘butterflies’ in the stomach as blood is diverted from the digestive system

Watch our Flight or fight animation to learn more about anxiety and the threat response.

Read transcript of The flight or fight response animation

Download our Flight or fight diagram as a pdf: