CORTISOL: FUNCTIONS, SYNTHESIS AND MECHANISM OF ACTION - NEUROPSYCHOLOGY - 2025

The cortisol is a glucocorticoid hormone produced by the adrenal gland. Its implications in the body are multiple and its main function is to increase the level of sugar in the blood and help the metabolism of fats. Likewise, it has an especially relevant role in stress states, becoming the hormone that we release the most in these situations.

Even if you have a high level of stress, you can have proper treatment, control blood cortisol and reduce its effects. If you act to combat it, you can avoid its negative consequences.

Structure of cortisol

In this article we will explain what are the characteristics of cortisol, what role a high cortisol plays in the functioning of the body, its causes and what we can do to get its level to be low and benefit our physical and mental health.

What is cortisol?

Cortisol, also known by the name of hydrocortisone, is a hormone in our body. Specifically, it consists of a glucocorticoid hormone, that is, it is one of the hormones that are responsible for the regulation of carbohydrate metabolism, promoting gluconeogenesis and suppressing the activity of the immune system.

Features

Cortisol is a hormone that all people secrete and that we need for the proper functioning of the body. In fact, this hormone performs regulatory functions in the body that are of vital importance.

Glucose metabolism and sugar regulation

Especially, it plays a key role in glucose metabolism and blood sugar regulation.

As found at Colorado State University, cortisol stimulates the production of glucose in the liver, moving specific amino acids from the tissues to the liver to be used in the production of glucose to feed the cells of the body.

Stops glucose absorption

Likewise, cortisol is the hormone that stops the absorption of glucose when its conservation is needed for survival and is capable of starting the breakdown of fats in cells for energy production.

In other words, the main function of cortisol is to extract from the food eaten the energy necessary to function properly.

Thus, if cortisol did not circulate in our blood, we could not produce glucose, so the cells of our body could not be fed, our tissues would not benefit from the substances ingested and no matter how much we ate, we would not nourish ourselves.

Therefore, cortisol plays a fundamental role in the correct development of our body because it allows us to transform the nutrients we ingest into food for the tissues.

Regulation of blood pressure

Likewise, cortisol also plays a very important role in regulating blood pressure. As a study published in the journal "Hypertension" showed, cortisol levels regulate blood pressure levels.

In this way, high levels of cortisol are related to high levels of blood pressure, low levels of cortisol with low levels of blood pressure and optimal levels of cortisol with good blood circulation in our body.

This fact has motivated many investigations that have shown how an excessively high cortisol release can easily cause hypertension, so an optimal release of this hormone in our body is important for physical health.

Other

Other important functions of cortisol in the body include the following:

• It helps the homeostasis of water and electrolytes (small substances that contain ions).
• It increases the level of sugar in the blood through gluconeogenesis (the process by which cortisol synthesizes glucose).
• Suppresses the action of the immune system.
• Decreases bone formation.

Synthesis

Like all hormones, cortisol is secreted in a particular area of ​​the body, which is responsible for its production. Specifically, cortisol is secreted by the reticular zone and stored in the fascicular zone of the adrenal cortex, the outermost part of the adrenal gland located in the kidneys.

At the same time, the release of cortisol by the adrenal gland is controlled by the hypothalamus, a specific region of the human brain.

This connection between the adrenal gland and the hypothalamus is of vital importance to properly understand the relationship between the brain and the human body, two structures that continuously feed back.

In this way, in stressful situations, the hypothalamus is activated due to nervousness and the external demands to which the brain is being subjected. When the hypothalamus is activated, it stimulates the adrenal gland, and encourages the secretion of cortisol, which is why it is released in greater quantity when we are anxious.

It may seem strange how a part of the brain can activate a region of the kidneys so immediately when we are subjected to states of stress.

Obviously, the functioning of the human organism is very complex, and the connection between the hypothalamus and the adrenal gland, between the brain and the kidney, is not linked by a magical direct information exchange route.

Mechanism of action

The path the "I'm stressed" message must take to get out of the brain and into the kidney is a bit longer and more complex.

The hypothalamus, in stressful situations, secretes a hormone called corticotropin-releasing hormone (CRH). This hormone is released in our brain (hypothalamus) and is conducted through the blood to the hypophysis, an endocrine gland located at the base of the skull.

As corticotropin-releasing hormone reaches the pituitary, it immediately releases another hormone, the adrenal hormone corticotropin (ACTH). This second hormone leaves the pituitary gland and is transported through the blood to the adrenal cortex.

When this hormone reaches the kidney, the secretion of glucocorticoids is stimulated, so the brain has already managed to connect with the kidney so that it releases more cortisol in our body.

In this way, we can observe a relationship between cortisol levels and stress states, which occurs through a cascade of hormone release that begins in the brain and ends in the kidney.

High cortisol

Cortisol performs very important actions for the proper functioning of the human body. However, this does not mean that the more cortisol we have, the more benefits our body will have.

Like all hormones, its excess can be as negative as its absence, since it can alter the functioning of such important body processes as those we have just discussed.

Likewise, if we analyze the actions of cortisol we can see how some of them can be harmful if they are carried out in excess.

We are not interested in the fact that blood pressure is excessively high, nor that the action of the immune system is constantly suppressed or that bone formation is constantly diminished.

In this way, cortisol is a totally essential hormone at certain times, especially those in which the body needs to metabolize glucose to feed the tissues.

However, the body does not need to carry out this process continuously, so there will be times when it will be convenient to have high levels of cortisol and times when it will be convenient for them to decrease.

Cortisol and the brain

As we have discussed, in stressful situations, the adrenal gland and the hypothalamus are connected by a cascade of hormones. In this way, when we live in a stressful situation, our brain sends signals to our kidney so that it increases the release of cortisol.

Therefore, when we are stressed there are greater amounts of cortisol circulating through the blood of our body.

The human body does not perform this process in vain, since the increased release of cortisol has an adaptive value, that is, our brain decides to tell our kidneys to increase the release of cortisol to meet a goal.

This goal is related to the primary reaction of humans to stressful situations that require increased anxiety and arousal.

In this way, our mind perceives stressful situations as emergency moments in which our body has to be more activated to be able to respond effectively.

Example

Some examples would be the anxiety that appears before the threat of a real danger, in which our body prepares to have the necessary energy to be able to respond effectively to said threat.

However, this adaptive function of our body works properly in specific moments of anxiety, in which the body is activated more than normal for a certain period of time, but returns to normal when the threat has disappeared.

In these situations, the greatest release of cortisol occurs during a short period of stress (while the state of nervousness lasts) and is restored when the anxiety has disappeared.

Continuous release of cortisol

However, the term stress does not refer to specific states of anxiety, but rather the opposite. Stress is understood as a permanent and prolonged state of anxiety, nervousness and agitation.

Therefore, when we are stressed, the release of cortisol increases continuously, so its levels increase and do not return to their initial state.

In this way, when faced with stress, our brain interprets the existence of a constant threat, so the adrenal gland continuously releases cortisol to provide the body with the necessary energy at all times.

However, in reality, in many moments of stress our body does not need an increase in energy since there is no real threat. Thus, the body begins to produce large amounts of cortisol for no real physical reason, so the hormone begins to harm our body.

Consequences of high cortisol

Excess cortisol in the blood produces negative effects such as an exaggerated elevation of sugar in the blood, increased blood pressure, osteoporosis, excessive hair production or the generation of stretch marks on the skin of the abdomen.

Likewise, high levels of cortisol can cause water retention in the eyelids, muscle weakness, weight gain in the trunk and physical exhaustion.

Therefore, stress not only damages mental health, but can also damage physical health in a direct way through the action of cortisol.

How can we lower cortisol?

Cortisol is a hormone that acts according to the needs of our body, so its production can be regulated through certain behaviors. As we have seen, high levels of cortisol cause great physical problems, so to decrease we will have to increase the care of our body.

Thus, in the same way that certain behaviors can become unfavorable to health through an increase in cortisol, others can become healthy behaviors that will reduce it.

There is a wide variety of hypotheses about factors that can influence cortisol production, however, the most important ones can be divided into three large groups.

Avoid stress

Obviously, as we have seen throughout the article, if you are stressed your cortisol levels will increase, so if you are not, you will protect your body more from the increase of this hormone. Therefore, it is important to avoid stress as well as to tackle it in time when it begins to appear.

Try to fill your schedule with a number of activities that you can do in a healthy way without overdoing it, spend some time each day doing things that you like, organize yourself well, and perform relaxation or meditation exercises when anxiety takes over.

Eat healthy

Cortisol plays a fundamental role in the metabolism of food, so these are also important in predicting the functioning of this hormone.

Try not to abuse products that contain large amounts of caffeine, reduce the amount of processed foods, moderate the consumption of refined carbohydrates such as white bread, chocolate or sweets, and hydrate yourself well during the day.

Exercise

An investigation of "The Journal of the International Society of Sports Nutrition" showed that the practice of physical activity allows to reduce the levels of cortisol in blood. However, it was also shown that excessively strenuous or long-lasting physical exercise produced the opposite effect and increased it.

Thus, to lower cortisol levels it is recommended to exercise regularly but without exceeding 45 minutes of training.

References

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3. Hammond GL, Smith CL, Underhill DA. Molecular studies of corticosteroid binding globulin structure, biosynthesis and function. J Steroid Biochem Mol Biol 1991; 40: 755-62.
4. Kriegsfeld LJ, Silver R. The regulation of neuroendocrine function: Timing is everything. Hormones and Behavior 2006; 49: 557-574.

Weigensberg MJ, Toledo-Corral CM, Goran MI. Association between the metabolic syndrome and serum cortisol in overweight Latino youth. J Clin Endocrinol Metab 2008; 93 (4): 1372-1378.