Cortisol: The 'Stress Hormone' That's Making You Ill

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We need it to survive, but too much of it could be making us tired, fat, anxious and arthritic. We explain what cortisol is, whether it could be affecting your health, and what you can do about it...

What is it?

Cortisol is a naturally occurring steroid hormone produced by the adrenal glands when we wake up, exercise or experience stress, but it's most commonly associated with the 'fight or flight' response. When released in response to a stressor, cortisol and epinephrine (otherwise known as adrenaline) cause a cascade of reactions to occur: the arteries narrow, heart rate increases, glucose floods the body, insulin production is inhibited and blood is diverted away from the digestive system and other organs towards the heart and lungs. Cortisol also regulates our bodies' use of energy, carbohydrates, fats and proteins, and can affect the functioning of other hormones, including oestrogen and progesterone (or the 'sex hormones')

What are its effects?

In small doses, cortisol can help the body to cope with stressful experiences, but it's geared towards tackling stressors which require a physical ('fight or flight') response. It doesn't necessarily help us to deal with the manifold psychological and emotional stresses which punctuate our everyday lives - from looming deadlines to train delays - the accumulation of which can cause our bodies to pump out an almost constant supply. At best, it's unnecessary. At worst, it could kill us.

The consequences of chronic over-production of stress hormones, or 'adrenal fatigue', may include:

Blood sugar imbalances and an increased risk of type 2 diabetes, due to chronic insulin suppression

Weight gain, particularly around the stomach and thighs, due to insulin suppression and increases in appetite (cortisol spikes trigger cravings for high calorie food) and fat storage

Heart disease and heart attacks, due to arterial constriction and increases in blood pressure

Reduced immune system function


Chronic fatigue


Thyroid disorders




Premature menopause

Hair loss

What are the symptoms?

The symptoms of adrenal fatigue are common to many disorders, but if you tend to experience a number of these symptoms regularly, over extended periods of time, it's likely that you are suffering to some degree. Recent estimates put the number of UK citizens suffering from stress-induced stomach aches at 88%. If your adrenals are out of balance, you may experience symptoms of 'hyper-arousal', under-arousal or a combination of the two.

Symptoms include:

High or low blood pressure

Frequent illnesses which you struggle to shake off

Nausea, heartburn, stomach aches or cramps, diarrhoea or constipation

Regular back or head aches

Feeling 'tired and wired' most of the time

A short fuse, accompanied by feelings of anxiety or feeling overwhelmed

'Brain fog' or racing thoughts

Cravings for sweet or salty foods

Abnormal weight gain, particularly in the abdominal or thigh areas

Trouble falling or staying asleep

Sleeping well but waking up tired

Low libido What can you do?

If it's not possible to remove the source of your stress, don't despair. There are several ways in which you can mitigate its effects on your body.

Daily mindfulness meditation decreases cortisol production by an average of 20%.

Music can moderate cortisol spikes. Try listening to soothing music on your way to a stressful event, or as a way to wind down before bed.

Get enough sleep. Over the course of a week, sleeping for 8 hours a night can cut the level of cortisol circulating in the bloodstream by 50% versus sleeping for 6 hours a night. If you fall short, a nap can help.

Drink tea. Research has found that the cortisol levels of regular tea drinkers fall more quickly than non-tea drinkers following stressful experiences. But beware - caffeine can trigger cortisol release.

Go for a rub down. A weekly massage can cut cortisol levels by almost a third.

Watch a comedy show or arrange to meet a funny friend. Simply anticipating laughter can reduce cortisol levels by 39%.

Keep your blood sugar stable by eating small, frequent, balanced meals and swerving refined carbs.

Stay well hydrated. Dehydration stimulates the release of cortisol.

Exercise regularly. Although exercise temporarily increases cortisol output, regular cardiovascular activity enables your body to adapt to both physical and emotional stressors, raising the threshold at which cortisol is released. Regular exercisers have been found to produce less cortisol in response to emotional stress.

Watch your posture. Recent research has uncovered neural connections between motor areas in the brain and the adrenal glands, leading neuroscientists to conclude that our posture, particularly the way in which we hold our core muscles, could have a direct impact on stress. Try yoga or pilates - the core-strengthening benefits could pay dividends in more ways than one.

Get it off your chest (or stomach). Scientists believe that women's 'more finely tuned nervous system' may make them more prone to stomach aches caused by 'internalising' stress. However, recent research has also discovered that women release the 'bonding hormone' oxytocin in response to stress, indicating that reaching out to friends and loved ones may be an evolutionary stress response. Yes, this is a legitimate excuse to rant, ladies.