Categories: Endocrinology

Stress Hormone and its effects

The body produces various hormones to manage innumerable functions or processes in the body, on a day-to-day basis. One such hormone is Cortisol. Since its most famous function is Stress Response, it’s called the Stress Hormone, however Cortisol is responsible for several functions in the body which include:

  • Stress Response: It boosts energy so that we can handle stress better, and once the stressor is gone, it helps restore balance afterwards
  • BP: It plays an important role in achieving salt and water balance, which helps regulate blood-pressure.
  • Glucose metabolism: Help in insulin release thereby regulating blood-sugar levels
  • Improves immune function
  • Inflammatory response: reduces inflammation
  • Regulates metabolism: Manages how our body uses carbohydrates, fats, and proteins consumed as food
  • Cognitive: assists with memory formulation
  • In pregnant women, cortisol supports development of the fetus
  • Controls our sleep and waking cycle

How is Cortisol controlled

Cortisol levels in the body vary throughout the day, following our sleep and waking cycle or the ‘diurnal rhythm’. So when we wake up, we need more energy, so cortisol levels rise automatically. But end of the day, when we are retiring to bed, less energy is required, so cortisol levels drop. When we do strenuous activity (physical or mental), or exercise, Cortisol levels rise in order to supply more energy. That is why, we are advised against doing stressful activities or exercise closer to sleeping time, as high levels of Cortisol in the blood can delay or disturb sleep.

Cortisol is secreted by two pyramid-shaped glands called adrenal glands, located one each, on the top of both the kidneys. However, secretion by the adrenal gland is controlled by the pituitary gland located at the base of the brain and the hypothalamus, a region within the brain associated with highly specialized functions. This exclusive connection between the three is called the hypothalamus-pituitary-adrenal axis or HPA axis. Two other hormones called corticotrophin-releasing hormone and adrenocorticotropic hormone (CRH and ACH) act as messengers that relay signals between these members to elicit the required response.

Cortisol and Stress Response

Life is full of stressful situations or ‘stressors’. These could be an animal attacking you, a traffic jam delaying your work, a looming deadline, a road to be crossed quickly, slamming brakes to avoid a collision, a payment that must be made when funds are short, a friend or family member being hospitalized, an accident at the workplace, a road accident, etc. In all these situations, the body gets into a ‘fight or flight mode” in order to surmount the crisis. The sequence is:

  • Adrenalin surges in the blood, increasing the heart rate and blood pressure.
  • The adrenal glands release cortisol into the bloodstream. This triggers a surge of glucose in the blood which supplies the excess energy required to large muscles of the body.
  • Simultaneously, Cortisol inhibits insulin production so that glucose will not be stored in the body but will be available for immediate use.
  • Cortisol also narrows the arteries to enable high blood-pressure, while another hormone epinephrine boosts the heart rate.

The sum total of all this is that, the heart pumps blood harder and faster in order to help you overcome the crisis quickly.

  • Cortisol also suppresses all those body functions or systems that are not vital during this fight-or-flight situation but would take up energy. So it alters immune system responses, suppresses the digestive and reproductive systems and slows down growth processes.

This complex process of managing a crisis, involves many players as you can see. This natural ‘alarm system’ is constantly communicating with those regions of the brain that control thoughts, feelings and emotions such as fear, desire, anger, hatred and pain.

Once the crisis is over, all the hormones and systems of the body return to their normal or healthy positions and life continues as usual.

How does excess Cortisol harm us?

However, in some people, this natural return to normalcy does not happen immediately. The body perceives the crisis to be ongoing, and this comes from the person’s thoughts and emotions. So cortisol levels remain high in the blood. Examples for these could be people working in stressful jobs or stressful workplaces, a toxic work-environment, domestic abuse, people recovering from injury or disease, people reliving memories of physical, sexual, verbal or mental harassment, reliving memories of past accidents and tragedies, soldiers who return from war and are reliving painful memories of the same, and all those people who suffer from Post-traumatic stress disorder (PTSD).

When high levels of cortisol in the body persist for a day or two, it’s still Ok, as the body can manage this level of stress. However, when the same continues for weeks or months on end, one by one, all the body systems start getting affected adversely.

Skeleto-muscular system

Muscles tense in response to stress, and then relax once the stressor is removed. However, when Cortisol levels remain high for long, muscles in the head, neck, back and lower-back are in a constant state of tension. This causes stress headaches and migraine headaches. Further, the combination of muscle tension and muscle atrophy (disuse of some muscle group) can cause several, chronic, stress-related skeleto-muscular conditions.

Respiratory System

In response to stress, the airway between the nose and lung contracts in order to enable rapid and deep breathing. When the stressor is removed, the airway returns to its normal position. But in people with high cortisol levels, the airway remains constricted, leading to constant shortness of breath (dyspnea) and rapid breathing (hyperventilation). For people who are already suffering from respiratory ailments like asthma, COPD, emphysema, and chronic bronchitis, the additional stress worsens the symptoms.

Cardiovascular system

In response to stress, the heart-rate and blood-pressure go up drastically as explained earlier. These conditions must return to normal once the stressor is removed. However, in people with high cortisol levels, the high blood pressure becomes a regular feature which increases the risk of inflammation in the circulatory system, hypertension, heart-attack and brain stroke. In pre-menopausal women, the high estrogen levels act as a protection against these risks. However, in men and post-menopausal women, who have low levels of estrogen, this protection is not available, so the risk is higher.

Endocrine system

As explained earlier, the HPA axis and several hormones come into play during a stress situation and are at elevated levels. However, when Cortisol levels remain high for long, the communication within the HPA axis and these hormones get impaired. This opens the door for many conditions in the future, such as immune-system disorders, chronic fatigue, depression, diabetes and obesity.

Gastro-intestinal system

The brain-gut axis and the gut-bacteria are vital for overall health, proper digestion, and positive mood. When cortisol levels remain high, organs in the digestive system are affected adversely.

  • Esophagus: Stress can increase the amount of air that is swallowed or make swallowing food difficult. Together, these lead to burping, gas (flatulence) and a bloated feeling. It can increase heartburn or acid-reflux in people who smoke or consume alcohol. It can also cause spasms in the esophagus which are often mistaken for a heart-attack.
  • Stomach: Stress causes a bloated feeling, discomfort or pain in the stomach, nausea and vomiting. However, stress does not cause stomach ulcers as wrongly believed.
  • Bowel: Stress can cause constipation, diarrhea and muscle spasms in the bowel which can be painful. For people with inflammatory bowel disease or irritable bowel syndrome, the symptoms worsen.

Nervous system

The autonomic nervous system is made up of the sympathetic nervous system (SNS) and parasympathetic nervous system (PNS). The SNS is what triggers all the body functions in a fight or flight situation, while the PNS is what tries to restore normalcy once the stressor is removed. In people with high cortisol levels, the SNS and PNS are constantly in a state of agitation. While this doesn’t harm the nervous system per se, it causes chronic wear and tear in all other body systems.

Male reproductive system

Chronic stress suppresses sexual desire (libido), and affects both sperm motility (ability to swim) and sperm morphology (shape and size). Both these factors can affect fertility in the man. Stress also suppresses the immune system increasing the risk of infection in the testes and prostate.

Female reproductive system

Chronic stress can cause anxiety and depression in women which affects their ability to conceive, affects their health during pregnancy and slows down post-partum (after delivery) recovery. Both pre-menopausal women and women going through a menopause can have worsened symptoms. Periods can get heavy and painful, irregular, less frequent or stop altogether (amenorrhoea). Finally, stressed women are more vulnerable to diseases like herpes simplex and polycystic ovarian syndrome (PCOS).

Immune System

Since cortisol levels are supposed to suppress the immune system during every episode, chronic stress means the immune system gets weakened eventually. The person is more prone to infections such as common cold, while recovery from injury or illness takes longer.

What is Cushing’s Syndrome

A tumor developing on, or close to – the adrenal and pituitary glands can render the HPA axis ineffective. In addition to the high cortisol levels in the blood, the person may exhibit rapid weight gain in the face, chest and abdomen while the limbs remain the same. The person may also experience mood swings, a flushed face and changes to the skin. He/she may also suffer from hypertension and osteoporosis.

How does low Cortisol harm us?

All the above information implies that high cortisol can cause innumerable conditions or increase the risk for disease. In the same way, low cortisol levels are also risky. Addison’s disease, or primary adrenal insufficiency is an auto-immune disorder in which cortisol is secreted by the adrenal gland in low quantities. This leads to mood swings, weight loss, muscle loss, fatigue and changes to the skin.

Outlook

Needless to say, cortisol levels must be healthy most of the time, which implies we must manage our stress very well. How to manage stress is an exhaustive topic in itself and deserves an entire blog dedicated to it. But the key takeaway from this article is that effective Stress Management is critical for both short-term and long-term physical, cognitive and psychological health, as well as good quality-of-life, well into the old ages.


Reviewed by Dr Suresh S Venkita, Group Medical Director, Kauvery Hospitals


Kauvery Hospital is globally known for its multidisciplinary services at all its Centers of Excellence, and for its comprehensive, Avant-Grade technology, especially in diagnostics and remedial care in heart diseases, transplantation, vascular and neurosciences medicine. Located in the heart of Trichy (Tennur, Royal Road and Alexandria Road (Cantonment), Chennai, Hosur, Salem, Tirunelveli and Bengaluru, the hospital also renders adult and pediatric trauma care.

Chennai – 044 4000 6000 • Trichy – Cantonment – 0431 4077777 • Trichy – Heartcity – 0431 4003500 • Trichy – Tennur – 0431 4022555 • Hosur – 04344 272727 • Salem – 0427 2677777 • Tirunelveli – 0462 4006000 • Bengaluru – 080 6801 6801

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