How does stress affect the brain?

The anatomy of our brain

As we read in the book on stress called Working on Yourself, the human brain is made up of parts. Some parts evolved earlier than others. The parts of the brain responsible for our survival are more primitive than those responsible for logical thought, language, and our other cognitive functions. For example, if you are confronted by a tiger, the brain will activate the fight or flight response. That is, it will prepare you to respond immediately to the threat, either by staying with it and fighting or by leaving as quickly as possible. The same happens with animals.

So when a signal is given for the fight or flight response, the sympathetic nervous system is activated. Specifically, in the brain with the amygdala, the fear center of the brain is activated.

In turn, the amygdala activates the central stress response system, also known as the hypothalamic-pituitary-adrenal (HPA) axis. This system controls hormones, specifically cortisol. Once activated, glucose levels, heart rates, and blood flow to the muscles of our arms and legs increase immediately.

This is done so that we can respond quickly and effectively to a threat. After the danger has passed, this system restores the hormones to their normal levels and the parasympathetic nervous system is activated. This is responsible for rest, relaxation, the ability to feel calm when the danger has passed.

Reality vs Fantasy

The problem with the brain is that it cannot tell when the tiger is real and when it is not. When you think something catastrophic is happening or will happen, whether it's a tiger or that you won't catch the bus, it makes no difference to the brain. The brain treats anything you perceive as a real threat, as a threat to your very survival, and then activates the fight or flight response. It is worth noting that when the response is activated the parts of the brain responsible for higher functions are under-functioning.

That's why many times when you feel intense anxiety and stress, you can't think rationally, and your ability to deal with a situation calmly and effectively is drastically reduced. This is because the fight-flight response has been activated and you do not have access to higher cognitive functions, which could help you solve any problem.

Unexplained fatigue?

Has it ever happened to you that you wake up fine in the morning, and even though all you've done all day is sit at a desk, when the evening comes you're dead from exhaustion? The answer is that the body is tired from stress. When the stress response system is on high alert often, something goes wrong. There is no balance between the sympathetic and parasympathetic nervous system, mental and physical problems can occur.

The same hormones that help the body respond effectively to a threat are the ones that can lead to chronic problems.

Digestive problems, sleep problems and a generally weak immune system. Other problems it has been linked to are increased risk of heart attack, diabetes, high blood pressure. In addition, an increased risk for depression and anxiety disorder.

Ways to reduce stress

There are many ways that can help you relieve stress.

For example, there is the medicinal route, which works at the level of the brain and body. Another option is the behavior change method. One is not better than the other and what you choose depends on many factors. Like what is available where you live, what suits you and what you are available to provide in terms of time and money. In this special book on stress, I will show you some methods by which you can act on the level of thought, which in my own experience is the cause of all unnecessary stress. Unnecessary because most of the time the threat is imaginary and there is no question of survival.

Read more in the book "Working with Yourself" from iWrite Publications