Noradrenaline and adrenaline are catecholamines that play major roles in regulation of the ‘inner world’ of the body by the brain. Noradrenaline (synonymous with norepinephrine), the main neurotransmitter of the sympathetic nervous system, is responsible for tonic and reflexive changes in cardiovascular tone. Adrenaline is a key determinant of responses to metabolic or global challenges to homeostasis, such as glucoprivation(increases expression of neuropeptide Y mRNA in hindbrain neurons that innervate the hypothalamus) and of manifestations of emotional distress. In contrast with the view that the sympathetic nervous and adrenomedullary hormonal systems function as a unit (the ‘sympathoadrenal system’) to maintain homeostasis in emergencies, across a variety of situations, adrenaline responses are more closely linked to responses of the hypothalamic?pituitary?adrenocortical system than of the sympathetic nervous system. The sympathetic noradrenergic system is active even when the individual is at rest and maintains tonic levels of cardiovascular performance. Adrenoceptors in the membranes of effector cells determine the physiological and metabolic effects of catecholamines.
Some stress is good for us, but when it is prolonged, stress is very bad for our health. We are simply not put together to deal with the kind of stressors that modern life often imposes on us. Imagine, while driving when there is a serious motor-vehicle accident right in-front of you, what happen to you? Your heart beat very fast, you feel light-headedness, your legs trembling, your eyes dilated. These are acute stress reaction and the effects are due to the release of catecholamines, a neurotransmitter. Noradrenaline and adrenaline are catecholamines that play major roles in regulation of the ‘inner world’ of the body by the brain
Now, when you are facing with life stressors and/or lifestyles stressors there are chronic persistent, sub-clinical (you are not aware) but there is high persistent level of catecholamines release and the release or another hormone by adrenal gland so called cortisol. Early morning blood or saliva test may indicate the effect of chronic stress on DHEA and Cortisol balance. Excess cortisol, a hormone critical in managing fat storage and energy use in the human body. Cortisol is known to increase appetite and may encourage cravings for sugary or fatty foods.
Stress is a bigger problem than you think
The prominent psychologist Richard Lazarus offers a similar definition: