By Maria Pavlatou, MD, PhD, Director of Endocrinology, Diabetes & Metabolism, Athens Medical Center
Stress is defined as anything that threatens the homeostasis of the organism and thus its existence. For this reason, the human body has developed a specialized system for dealing with stress and restoring regularity. This system responds to the various stress stimuli, with an inherent, stereotyped response, including cognitive, behavioral and physical changes.
The central mechanism of this system is located in the brain and is the hypothalamic-pituitary dipole. The hypothalamus is the central coordinating organ of all neuroendocrine functions and a basic regulator of homeostasis. It accepts messages from other parts of the brain, the other organs of the body, and the external environment, and after processing them, gives the appropriate commands.
In stress, orders are directed to the third organ of the system, the adrenal glands, which increase the production of cortisol, and catecholamines. The rise of these hormones, in collaboration with the autonomic nervous system, marks a series of changes, such as:
- increased cardiovascular function and metabolism, to mobilize the body and provide fuel for the precious brain,
- suppress energy-consuming functions, such as that of reproduction, in order to save energy,
- stimulate attention and alertness to achieve preparedness and concentration in the treatment of stress,
- mobilize inflammation to deal with potential trauma and
- increase the pain threshold.
The above changes are adaptive as they increase the chances of survival during stress. But when the stress is over, the system is self-extinguished, and so all the above functions return to normal.
If stress is not addressed, survival is not possible.
What if the size and / or type of stress is such that on the one hand it does not make survival impossible but on the other hand it is not treated and therefore keeps the stress axis (hypothalamus, pituitary gland, adrenal glands) chronically activated?
In this case, a series of early serious pathologies appear, ultimately reducing both quality of life and life expectancy. Modern lifestyles have many of these examples of stress that did not exist in the early evolutionary stages of human progress and for which the body is not ready to cope. Such examples of stress are:
- hyperphagia and fattening foods of low nutritional value,
- stress over social and professional progress,
- aging and life expectancy,
- changes in the biological rate of light vs dark and exposure to artificial light also in the evening,
- inhalation of chemicals and pollutants,
- sedentary life and lack of physical activity.
These stimuli do not directly threaten life, but are alien to human nature, and thus mobilize the mechanisms of protection against stress (which are normally employed in the short term in urgent situations), chronically.
Chronic growth of stress hormones - catecholamines and cortisol - leads to a series of endocrine and systemic disorders, which often do not find a solution, as both their diagnosis and treatment require a thorough knowledge of the neuroendocrine system of the stress system.
In these cases, we should turn to an endocrinologist to correct the pathology in depth and propose appropriate treatments.
