Stress - Positive or Negative?

There are forms of "positive" stress, such as exercise or challenging situations, for example, and "negative" ones, such as sleep deprivation or problems at work/personal life. How we adapt to these situations mentally and physically will work positively or negatively on our bodies.

Our body has a system for responding and adapting to stress, which aims for a state of balance. But what can happen if this system is subjected to an excessive load? This question will be explained later!

The structures responsible for the stress response are the hypothalamus, the pituitary gland, and the adrenal glands. The hypothalamus and pituitary gland are located at the base of the brain and function, together, as the masters of hormonal regulation in the body. The adrenals are two specialized glands, situated above the kidneys, which produce, under "order" from the pituitary, the hormones and neurotransmitters responsible for promoting the physiological adaptations necessary to restore balance. This system is called the Hypothalamic-Pituitary-Adrenal (HPA) axis.

When a stimulus is perceived as a stress agent, the hypothalamus triggers a cascade of signals that leads to two types of response:

In an ideal situation, stress is resolved, and these responses are terminated.

All fundamental substances for the body's functioning are subject to rigorous control. Cortisol is no exception and obeys a circadian rhythm. Cortisol secretion is maximal about 30-45 minutes after waking, resulting from the stimulation of the hypothalamus by natural light. This morning peak of cortisol is essential for us to have energy to start the day. From then on, levels decrease and should be low at night, to allow for sleep. When cortisol levels are too high, the hypothalamus, through its sensors, detects this situation and decreases the signaling for hormone production (negative feedback mechanism).

When there is no resolution of stress (whether psychological or physical), there will be constant pressure on the HPA axis, in the direction of cortisol production. Initially, this results in increased cortisol production. However, over time, hypocortisolism can develop, in which the body activates a series of mechanisms to lower cortisol levels and thus self-protect against its deleterious effects. It is important to remember that cortisol is a catabolic hormone, which promotes the degradation of tissues such as muscle and bone, prioritizing other functions more important for survival. As such, continuously high levels of this hormone represent a metabolic risk.

What are the symptoms of hypocortisolism (lack of cortisol)?

When the HPA axis is suppressed and cortisol levels decrease, we are facing a situation of "burnout" or exhaustion. The most common symptoms are: extreme fatigue, muscle weakness, diffuse pain, depression, irritability, and difficulty concentrating. It is important to distinguish this state of hypocortisolism from Addison's disease, in which there is an autoimmune destruction of the adrenal gland, and consequent decrease in cortisol levels. In HPA axis dysfunction due to chronic stress, the problem does not lie in the adrenal glands, but in the regulatory mechanism commanded by the hypothalamus and pituitary.

To answer this question, we will use the four main enhancers of the HPA axis, highlighting, in a simplified way, what can be done in each category to increase our resilience to stress.

1. Perception of stress – all stressful situations are uniquely perceived by different individuals. It is important to have tools that allow us to put stress into perspective and find solutions for adverse situations, if necessary, with the help of specialized professionals.

2. Maintenance of circadian rhythm – the routine of light/dark cycles is fundamental for the correct functioning of the body, including the maintenance of healthy cortisol levels. The ideal is 7-8 hours of continuous sleep, between 9:00 PM and 8:00 AM.

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