Adrenaline has many different actions, however, the overall effect of adrenaline is to prepare the body for ‘fight or flight’ mode in times of stress.  Key actions of adrenaline include raising the heart rate, increasing blood pressure, expanding the air ways in the lungs, enlarging the eye pupils and changing the body’s metabolism, so as to max out blood glucose levels (mainly to the brain).  This is all so that we can jump to action when presented with a threat.  When we talk about stress this doesn’t just mean a hard day at the office it includes any stress placed on the body including anger, fear and physical exertion. We need adrenaline to exercise and even just thinking about exercise can increase adrenaline production. This is why quite often after exercise one can experience a euphoria, it’s the adrenaline rush that creates this feeling throughout the body triggering neurotransmitters such as endorphins which can leave us with an incredible natural high.  Adrenaline is a wonderful thing and we wouldn’t be able to get through life without it. However, high levels of stress on the body can cause an over production of adrenaline which can lead to feelings of anxiety and fatigue. It causes the body to be in a constant sympathetic nervous state with very little time to rest and digest.