Anxiety is a physiological and psychological response which is experienced when the fight or flight response has been triggered. The fight or flight response is a survival mechanism experienced by all human beings, as when we were cave people we lived outside and the world was a dangerous place. The fight or flight response is usually triggered in response to a variety of stressors in our environment (such as a threat to our safety) and as a result the body experiences a range of psychological and physiological responses including, somatic, emotional, cognitive and behavioural reactions which are designed to keep us safe in dangerous situations.
Say for example you were out gathering food for your family and a sabre tooth tiger came along. To protect yourself in this situation your body would experience a range of physiological changes designed to enhance your survival by giving you the energy to either run or fight for your life.
Adrenaline and stress hormones would be released into the blood stream, your blood pressure and heart rate increase to pump blood to your vital organs, your breathing becomes shallow as your body tries to get more oxygen to the lungs, your muscles tense up as your prepare to either fight or run, you feel fear as you know something could happen to threaten your survival, your digestion system slows down or stops, you body starts to sweat to regulate your body temperature, you get tunnel vision and can only focus on the danger in front of you and you begin to think about all of the different worst case scenarios as you attempt to prepare for any eventual outcome.
This physiological response is still very helpful in modern day society in times when there is a threat to our safety, for example if you were crossing road and a car came speeding towards you, the reactions experienced during the fight or flight response would help you to assess the danger and run out of the path of the vehicle. However, often times in modern day society our stresses are not life and death situations with simple solutions (if you are danger you run, if you cannot run you fight and if you can’t fight you freeze) but are often complex situations which cause ongoing stress and do not have simple solutions, such as paying our bills, dealing with interpersonal conflict, struggling in stressful work environments, raising children etc.
As a result we all experience anxiety at different times during our lives but some people develop anxiety disorders.