Cortisol: Its Role in the Body and Adrenal Exhaustion

4.2.2026

Inspiracja

Cortisol: Its Role in the Body and Adrenal Exhaustion

Stress is a natural part of life, and cortisol is one of the key hormones that help the body cope with it. In the short term, it acts as a "lifesaver" and its effect is essential – it mobilizes energy, supports alertness, and allows a quick response to stress. However, when stress is chronic and cortisol levels remain elevated for an extended period, this protective mechanism can become a factor that gradually depletes the body and disrupts overall health.

What will you learn in this article?

Cortisol hormone
What are the functions of cortisol in the body?
Long-term stress and adrenal exhaustion
How adrenal exhaustion manifests
How cortisol levels can be measured
How to support adrenal function
Adrenal cocktail
Key takeaways from the article

Cortisol hormone

Cortisol is a steroid hormone that belongs to the glucocorticoid group and is produced in the adrenal cortex. Cortisol production in the body is regulated by a system known as the HPA (hypothalamus-pituitary-adrenal) axis, which maintains hormonal balance and enables the body to respond to both internal and external stimuli. Cortisol is not just a “stress hormone” – although it is often associated with stress, its functions go far beyond stress response and impact many physiological processes necessary for maintaining balance in the body.

What are the functions of cortisol in the body?

Cortisol affects metabolism, immune system, sleep quality, and mental resilience. Therefore, proper regulation of cortisol is not only important for stress management but is crucial for overall health, regeneration, and long-term vitality. Understanding how cortisol works in the body and what affects its levels is the first step towards consciously building resilience to stress and better care for one's health, including the prevention of lifestyle diseases.

Metabolism and energy availability

As part of metabolic processes, cortisol is key in managing energy. During a stress response, it ensures the release of sugar into the blood to provide the necessary energy and prepares the body for the “fight or flight” response. However, if the body is chronically stressed, this originally protective response can lead to long-term elevated blood sugar and associated risks.

Immune system and inflammation

Cortisol also has a strong influence on the immune and inflammatory response. Short-term, it acts anti-inflammatory and suppresses immune responses, which is important during acute stress. However, chronically elevated levels can make the immune system less sensitive, and its function may be weakened, contributing to a higher susceptibility to infections and inflammation.

Stress response

Cortisol is one of the main regulators of the body’s response to stress. It activates during physical stress (e.g., physical strain, injury, or the need to defend against a threat) or psychological stress (e.g., anxiety, pressure). In the acute phase, it helps rapidly mobilize energy, increases alertness, and supports concentration. This hormone enables the body to effectively respond to challenges and threats.

Blood pressure and cardiovascular system

Cortisol also participates in regulating blood pressure by modulating vascular tension, sodium and water balance, and interaction with other hormones. Higher cortisol levels are associated with an increased susceptibility to hypertension, while low levels may contribute to low blood pressure and heart weakness.

Sleep and circadian rhythm

Cortisol plays a key role in the daily rhythm and circadian regulation. Its levels are typically highest in the morning to help wake up the body and prepare it for daily activity. In the evening and night, it should decrease to support falling asleep, deep sleep, and not hinder melatonin secretion, the sleep hormone.

Disruption of this rhythm (e.g., due to chronic stress or poor sleep habits) leads to poor sleep quality, fatigue, and slower recovery. In the long term, chronic high cortisol levels in the body can lead to "adrenal exhaustion," causing fatigue syndrome.

Nervous system and mental resilience

Cortisol also influences the nervous system and brain functions, including mood regulation, motivation, and cognitive processes. Proper cortisol levels help maintain the ability to adapt to stress, while long-term dysregulation can contribute to anxiety, depressive symptoms, and decreased mental resilience.

Long-term stress and adrenal exhaustion

The term “adrenal exhaustion” (or adrenal fatigue) is used in holistic medicine to describe a state where chronic stress depletes the adrenal glands and reduces their ability to produce hormones, particularly cortisol. Long-term emotional or physical stress can lead to overall fatigue, reduced stress resistance, sleep disorders, and energy crashes.

The gradual reduction in adrenal function occurs in several stages, which are related to the functional imbalance of the HPA axis (hypothalamus–pituitary–adrenal) and the body’s adaptation to persistent stress factors.

Chronic stress and activation of the stress axis

Long-term psychological, emotional, or physical stress activates the sympathetic nervous system and the HPA axis, which controls cortisol production. Initially, cortisol increases as an adaptive mechanism that helps mobilize energy and cope with stress.
If stress persists, it can disrupt the regulation of the HPA axis. Cortisol is then released irregularly, disrupting the body’s ability to respond to stress flexibly and maintain energy balance.

Decreased adaptive capacity of the body

During prolonged stress, the adrenal glands remain in a constant alert mode, which can lead to exhaustion and a reduced ability to secrete other hormones, fatigue, lower energy, poorer recovery, and symptoms known as adrenal fatigue.

Impact of lifestyle and environment

This condition can be further worsened by factors such as lack of sleep, irregular eating, high intake of sugar and caffeine, and deficiency of key nutrients.

How adrenal exhaustion manifests

Chronic fatigue and reduced energy

feeling exhausted even with sufficient sleep
typical morning fatigue and “getting started until noon”
reduced physical and mental endurance

Reduced stress tolerance

exaggerated responses to common stressors
feeling overwhelmed, inner tension
inability to calm down quickly after stress

Sleep disturbances

trouble falling asleep or frequent nighttime awakenings
feeling “tired but overstimulated”
poor quality, non-refreshing sleep

Psychological symptoms

irritability, mood swings
anxiety, reduced mental resilience
poor concentration, “brain fog”

Energy fluctuations throughout the day

significant energy drops in the afternoon
need for caffeine or sweets to “boost” energy
short-term improvement after stimulants, followed by a downturn

Hormonal and metabolic signals

cravings for sweets or salty foods
unstable blood sugar levels
poor recovery after exertion

Immune system weakness

frequent colds
slower recovery
weaker response to infections

How cortisol can be measured in the body

Blood test from serum

What it measures: current cortisol level at a given moment
How it's done: blood collection, usually in the morning (between 7:00 and 9:00)

Saliva (salivary cortisol)

What it measures: free (biologically active) cortisol
How it's done: saliva collection, done multiple times throughout the day

DUTCH test (Dried Urine Test for Comprehensive Hormones)

What it measures: not just free cortisol, but also its metabolites (cortisone) and shows the daily curve

Urine (24-hour collection)

What it measures: total amount of cortisol excreted over 24 hours

Cortisol levels from hair

What it measures: long-term cortisol exposure (weeks to months)

How to support adrenal function

Supporting adrenal function primarily involves normalizing the body’s stress response and reducing the long-term load on the HPA axis. Meditation and other stress-relieving techniques can help, as well as supplementation of specific nutrients like vitamin C for immune support, ideally in natural forms like acerola. Magnesium bisglycinate is important for regulating the stress response and the B vitamin complex - especially vitamin B5 and B6 support the health of the nervous system. Regulating stress can also be supported by supplementing vitamin D and ensuring its adequate levels in the serum, which should ideally be in the range of 100-150 nmol/l 25 (OH) vitamin D.

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Adrenal cocktail

An adrenal cocktail is a simple drink used primarily in functional medicine as a supportive tool for regulating the stress response and supporting the adrenal glands. It is a combination of nutrients that the adrenals quickly consume during stress. Drinking this cocktail can help regenerate their function.

Mix all the ingredients in water and drink. We recommend doing this in the morning before breakfast.

Key takeaways from the article

Cortisol is an essential hormone that helps the body manage stress, regulate energy, immunity, blood pressure, and sleep – the problem is not its existence, but long-term imbalance.
Chronic stress disrupts the natural daily rhythm of cortisol.
With prolonged stress, functional exhaustion of the HPA axis' adaptive capacity can occur.
Typical symptoms include chronic fatigue, energy fluctuations, reduced stress tolerance, sleep disorders, and frequent infections.
Cortisol can be measured using various methods, with salivary tests reflecting its daily curve and response to stress best.
An adrenal cocktail can serve as a simple supportive tool that provides the adrenals with key nutrients consumed during stress.
The foundation of long-term balance is not “suppressing stress,” but increasing the body's ability to adapt to stress.