Daijiworld Media Network - Bengaluru

Bengaluru, Sep 14: Cortisol is often described as the body’s “stress hormone”, but its role extends well beyond the response to stressful situations. Produced by the adrenal glands and regulated through the hypothalamic-pituitary-adrenal (HPA) axis, cortisol helps control blood sugar, metabolism, blood pressure, immune function and the sleep-wake cycle.

Cortisol naturally rises and falls during the day, with levels generally highest around waking and declining towards night. An acute stressful event can also temporarily increase cortisol levels. This is a normal response that helps the body mobilise energy and remain alert.

The concern arises when the stress response is persistently activated or cortisol regulation is disrupted over a prolonged period.

“Although called the stress hormone, cortisol is more than just a stress hormone,” said Dr Narendra BS, Lead Consultant, Endocrinology & Diabetology, Aster Whitefield Hospitals. He explained that a temporary rise in cortisol during stress is natural and can be beneficial by helping mobilise energy and maintain alertness.

However, prolonged cortisol elevation can affect several aspects of health. It may contribute to weight gain through multiple pathways, including increased availability of glucose, changes in appetite and a greater preference for calorie-dense or high-sugar foods. Excess cortisol may also influence fat distribution, with increased fat deposition around the trunk being associated with prolonged cortisol exposure.

Dr Narendra cautioned that stress does not automatically result in weight gain. Sleep, eating habits, physical activity and individual differences in HPA-axis regulation also play important roles in determining body weight.

Cortisol also helps maintain blood glucose by signalling the liver to produce more glucose and temporarily reducing insulin sensitivity during physical or psychological stress. This provides additional energy to the brain and muscles during short-term challenges.

However, prolonged cortisol elevation may contribute to insulin resistance. “However, if the elevation in cortisol level continues for long enough, one can start to experience insulin resistance,” Dr Narendra said.

Reduced insulin sensitivity over time can make it more difficult for the body to regulate blood glucose and may increase metabolic risk, particularly among people who already have risk factors for diabetes.

Cortisol also plays a role in maintaining blood pressure and cardiovascular function. Persistent excess cortisol can contribute to hypertension through effects on blood vessels and the body’s salt and water balance. Cushing syndrome, a rare condition involving prolonged exposure to excessive cortisol, can be associated with high blood pressure, weight gain and elevated blood sugar.

The hormone also follows a circadian rhythm, normally increasing towards morning and declining during the day. This rhythm helps coordinate the body’s transition between sleep and wakefulness.

Chronic stress can interfere with this regulation. Continued activation of the stress response may make it harder to fall asleep, remain asleep or feel adequately rested. Poor sleep can in turn affect appetite, energy, mood and metabolic health, creating a cycle in which ongoing stress further affects sleep quality.

Cortisol also interacts closely with the brain and the body’s stress-response system. Persistent stress and altered HPA-axis activity have been associated with changes in mood, cognition and emotional regulation.

People experiencing chronic stress may report anxiety, low mood, mental fog and emotional instability, Dr Narendra said. However, he cautioned against attributing mental health conditions solely to cortisol or an overactive HPA axis.

“Yet, you should not blame mental disorders entirely on overactive hypothalamus-pituitary-adrenal glands,” he said, noting that psychological, biological, social and environmental factors can all contribute to mental health conditions.

A single cortisol measurement also cannot establish that a person has chronically elevated cortisol. Cortisol levels naturally vary according to the time of day and circumstances. Conditions such as Cushing syndrome require appropriate clinical assessment and validated biochemical testing.

Persistent and progressive symptoms may warrant medical evaluation. These can include unexplained weight gain, particularly around the trunk, high blood pressure, elevated blood sugar, muscle weakness, easy bruising and characteristic purple stretch marks.

The key point is that cortisol itself is not harmful. It is an essential hormone that helps the body respond to challenges and maintain several vital functions.

Concern arises when there is persistent cortisol excess or prolonged disruption of the stress-response system, particularly when it is accompanied by changes in weight, blood sugar, blood pressure, sleep or other symptoms. People experiencing persistent changes should consult a doctor rather than assuming that “high cortisol” is the underlying cause.