We all have innate survival mechanisms. For example, if we were to meet a dangerous animal in the wild, as our ancestors may well have done, we would feel an immediate surge of fear. Our bodies would then undergo a number of physical changes designed to prepare us to fight or to run away:

• adrenalin and other chemicals would be released into the bloodstream
• heart rate, blood pressure and breathing rate would increase
• digestive processes would be temporarily halted to save energy (emptying bladder and bowels to get rid of surplus weight)

The fight or flight which followed would then burn up all the increased energy and internal chemicals. When the frightening event was over, the body could then return to normal, without experiencing any stress.

In the modern world, we rarely find ourselves in situations where either fighting or running away would be an appropriate response. For example, an office conflict can trigger all our physical fight/flight responses, but without the opportunity to use them for their original purpose. Stress therefore occurs in situations where fear is present, but there is no fighting or running to burn off the chemicals released into the bloodstream. These chemicals can have a seriously adverse effect on our bodies and our health over time.