Stress is an eternal companion of humanity. Some people are stressed before public speaking, while some others feel stress by the economic or political situation in the country. In contrast, others suffer from anxiety caused by a disease or the loss of family members.
The countless causes of stress make it a lifelong companion. Surprisingly acute stress can play a positive role. It helps people keep alert and be ready for life-threatening defense responses. On the other hand, chronic stress may lead to many diseases like heart diseases, high blood pressure, depression, and even anxiety. Here, we aim to explain the chemical and biological essence of stress and its influence on humans.
Stress as a cocktail of hormones
Stress is a negative emotion that may have many faces like anxiousness, fear, and even panic. It is like a chain reaction. Stimuli cause the following release of chemical substances that cause body response. When a person experiences a stressful situation, the brain’s area associated with processing emotions, the amygdala sends an anxiety signal to the hypothalamus .
Moreover, the amygdala is active continuously, without any interruption. Even when we are entirely safe, and there is no danger. Even now, when you read this article, it still analyzes and processes information about the environment without the participation of consciousness.
The source of the negative feelings associated with stress stems from hormones released in our bloodstream and trigger body reactions. The main stress hormones are adrenaline and cortisol .
The first one triggers the metabolism of carbohydrates and primes the body to action. It spontaneously causes increases in heart rate, blood pressure, and boosts energy supplies. Simultaneously, cortisol increases the glucose level in the bloodstream, but it is not the end. It also influences the immunological system, fat metabolism, and much more.
The adrenaline effect on the body looks quite simple. However, it is a complex process that causes several following processes in many organs. Cortisol controls how the body uses fat, proteins, carbohydrates, and minerals and reduces inflammation in the organism. It brings alertness to our minds and makes us ready for challenges. Both hormones work together like an alarm to our brain and influence motivation, mood and cause even anxiety, fear, or panic .
Cortisol is in our body even if we are not stressed. It helps the body respond not only to stress but also to danger. Cortisol increases glucose metabolism, controls blood pressure, and reduces inflammation. However, we want it or not. Stress is a common experience of daily life .
Various sorts of stress
We all struggle with stress, so our body has its way how to deal with it. How? Of course, biologically, using the sympathetic and parasympathetic nervous systems that regulate each other. These are autonomous nerve systems beyond our brain’s control that regulate the most crucial functions of our body. The sympathetic one quickens the pulse, increases the glucose delivery from the bloodstream to muscles, causes sweating or tears production, while the parasympathetic works oppositely relaxing muscles .
Stress is the general reaction of the organism to a frightening situation or stimulus. It is conditioned in human genetics and experience. We can divide stress into two main categories: positive stress that is called eustress, and negative stress, called distress .
The most common is the first one. It is quite natural and associated with important events in life like an exam or a performance in front of people. This brief, positive, and transient stress causes a temporary increase in stress hormones in the body and generally has no long-term side effects. Stress is not always a bad thing, as the release of adrenalin and other stress hormones may help increase one’s concentration or energy e.g., during public speaking.
The second type of stress, the typically long-lasting negative one, usually has a harmful effect on our body, in particular the brain. When a person is under chronic stress, their body produces more cortisol than it should be released, which leads to brain malfunctioning. As a result, it may disrupt the transmission of signals in our brain and, as an effect, leads even to phobia or psychological disorders. In general, chronic stress begins to change the functioning of our brain, and the changes it causes may have long-term health consequences.
Did you know that stress may also lead to the degradation of the neural cells and reduce the size of the brain? Chronic stress causes a decrease in the area of the brain responsible for memory and learning that is located in the prefrontal cortex of our brain.
There are many harmful effects of long-term exposure to stress. It may impair health by increasing the risk of infections, and it can contribute to the development of autoimmune diseases in extreme cases. Did you know that it may also lead to mental disorders? One of them is post-traumatic stress disorder called PTSD .
Traumatic situations like the loss of a loved one or serious accidents are the most likely causes of PTSD. When, in addition to chronic stress, we experience additional sudden stress appear changes in neurons like inflammation and changes in the organization of some nervous connections. As an effect, people with PTSD may become more sensitive to some stimuli than others and be prone to overreacting. Such reactions are spontaneous and not controlled. PTSD may have many faces like nightmares, brain fog, nightmares, headaches, feeling emotionally numb, and many more.
Probably, the most common mental disorder that is caused mainly by stress is depression . A permanent high level of this hormone affects neurons (nerve cells), especially in the hippocampal area that plays a significant role in learning and memory. So, when neurons from this part of the brain are affected, it leads to negative feelings like sadness, emptiness, hopelessness, permanent fatigue, problems with concentration, and much more. Moreover, elevated cortisol levels may lead to symptoms like weight loss or weight gain, insomnia, lack of appetite .
What about schizophrenia? Unfortunately, in some particular cases, it is also related to stress. It is one of the most complex mental diseases in modern psychiatry. This disease belongs to the psychotic disorders group. It can be caused by factors like prenatal lesions, neurodevelopmental disorders, neuroendocrine disorders in the age of adolescence, and early youth.
However, research in this field has confirmed the connection between chronic excessive stress and the first episode of schizophrenia. Stress can trigger the first episode and increase the risk of relapse. However, stress is not the only one-factor causing schizophrenia .
It is difficult to measure stress, while its profound influence on the human body, brain, and overall functioning remains unclear. When it appears, it may assume different forms – sometimes it acts as a motivator to do something.
At the same time, prolonged exposure to stressful situations may cause serious health problems like insomnia, headaches, or even mental disorders. We can avoid the unpleasant and often dangerous consequences of stress to learn to deal with stress. Otherwise, it may even directly or indirectly kill you.
This article is a joint work of Emilia Cywińska (Faculty of Chemistry, University of Warsaw), Klara Ferenc (Faculty of Chemistry, University of Warsaw), Jakub Hilus (Faculty of Chemistry, University of Warsaw), Agnieszka Pregowska (Institute of Fundamental Technological Research, Polish Academy of Sciences), Magdalena Osial (Faculty of Chemistry, University of Warsaw) as a Science Embassy project. Figures Credit – M.Osial
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