What is Cortisol Hormone?

Cortisol, known as the “stress hormone,” is produced in the adrenal gland, specifically within the adrenal cortex, which plays a pivotal role in the synthesis of this vital hormone. This production process is significantly influenced by the adrenocorticotropic hormone (ACTH) released by the pituitary gland, which stimulates the adrenal cortex to produce cortisol. As a type of steroid hormone, cortisol is crucial for the body's response to stress and in the regulation of metabolism across various tissues.

Cortisol regulates many processes in the body in an effort to maintain homeostasis, including the fluctuation and regulation of cortisol production throughout the day and night, in alignment with circadian rhythms. Normal cortisol levels peak in the early morning at about 8 am and drop to their lowest levels by about 4 am. Just the event of waking up in the morning triggers cortisol secretion in the body, as does exercising.

Chronic stress can lead to persistently high cortisol levels, affecting various bodily functions, including blood pressure regulation. Elevated cortisol levels over time can contribute to conditions such as Cushing's syndrome and metabolic syndrome. Cushing's syndrome is characterized by symptoms like weight gain, high blood pressure, and skin changes, while metabolic syndrome includes a cluster of conditions such as high blood sugar, excess body fat around the waist, and abnormal cholesterol levels.

On the other hand, adrenal insufficiency, where the adrenal glands do not produce enough cortisol, can lead to significant health issues. Measuring cortisol levels can be done through various methods, including salivary cortisol tests, which are useful for assessing the hypothalamic-pituitary-adrenal axis function and diagnosing conditions like adrenal insufficiency.

Cortisol Essential Hormone In Response to Stress

When stressful events occur, the adrenals release cortisol into the bloodstream in an effort to prepare the body for fight or flight. This floods the body with glucose, providing an immediate source of energy to large muscles, also inhibiting insulin storage. Chronic stress can lead to elevated cortisol levels, resulting in prolonged effects on the body.

Cortisol works to narrow the arteries as epinephrine speeds up the heart rate, causing blood to pump faster and harder through the body as well. In response to stressors, cortisol regulates:

• Blood sugar (glucose)
• Fat, protein, and carbohydrate metabolism needed to maintain blood glucose (gluconeogenesis)
• Immune responses
• Anti-inflammatory responses
• Blood pressure
• Tone and contraction of heart and blood vessels
• Central nervous system

Chronic cortisol secretion can have several adverse effects, including elevated blood pressure and blood glucose levels. It is essential to measure cortisol levels accurately to assess the impact of stress on the body and manage conditions associated with abnormal cortisol production effectively.

Prolonged Circulation of Cortisol—Negative Effects

Although it is necessary for the adrenal glands to produce more cortisol as a direct response to stress, it is also very important that the body returns to a normal state of rest following a stressful event.

This allows cortisol levels to return to normal. When the body is exposed to chronic stress, too much cortisol circulates in the bloodstream causing adrenal fatigue and may result in serious health consequences such as:

• Impaired cognitive performance
• Lowered thyroid function
• Imbalances in blood sugar including, hyperglycemia
• Decrease in bone density
• Sleep disturbances
• Decreased muscle mass
• Elevated blood pressure
• Lowered immune function
• Slower wound healing
• Increased abdominal fat
• Mild depression
• Fatigue (morning, mid-afternoon)
• Inflammation

Weight Gain and Cortisol Glucocorticoid Hormone

As the body releases more and more cortisol in response to stress, fat storage occurs deep within the abdomen. Additionally, high blood glucose levels coupled with insulin suppression lead to glucose-starved cells.

These cells, in need of energy, send intense hunger signals to the brain, causing individuals to often overeat. Any unused glucose is stored as fat as well. Cortisol is also known to affect appetite cravings for high-calorie foods, as well as modulate other hormones known to stimulate the appetite.