What does cortisol do: signs of stress

 

What do depression, skin rashes, stomach aches and high blood pressure have in common? They can all be signs of stress. And there are many other possible symptoms and consequences that long-term stress brings with it. If your body constantly releases cortisol – that is, stress hormones – this can cause chain reactions throughout the body and have a lasting negative impact on your well-being and health.

Chronic stress is where your body is in a constant state of emergency. Stress becomes a problem when it is long term. The regular presence of stress hormones is unnatural for the human body – and it is ill-equipped to handle stress over a longer period of time.

Think about our ancestors: when hunting predators, they had an option between fight or flight responses in order to survive. These responses were usually over relatively quickly, subsequently allowing the body to rest, stress hormones to decrease and blood pressure to drop. Symbolically, stress thus guaranteed their survival. They were also exposed to stress – but to stress of a different kind compared to today. 

These days, stress that occurs in everyday working life, for example, can last much longer and become constant. In such cases, cortisol levels are also higher over the long term – and with it, pulse, blood pressure and blood sugar. In addition, chronic stress often disturbs the quality of sleep. Combined, these signs of stress can really mess up the body.^[1] 

Read this article to find out why stress can make you ill in different ways, what the most common stress symptoms and high cortisol levels are and how long-term stress is linked to stomach pain and gut health, headaches and skin rashes.

What is the best definition of ‘stress’?

Just over one-fifth of people declare themselves to be very happy. The ratio is more than twice as high as for stressed people.^[2] Everybody knows the term ‘stress’ and most people have already experienced stressful times. Stress is the human body’s reaction to a stressful situation, and this reaction is triggered by a stressor. A stressor can be any external stimulus or event which causes stress to an organism. Situations that are regarded as threatening or unpleasant can also be stressors. Disappointment, fears of failure and low self-confidence are the most severe stressors.^{[3, 4]}

The term ‘stress’ has gained increasing popularity in recent years. According to a Forsa study, around 80 per cent of 36- to 45-year-olds suffer from stress, in school or at university and also from financial worries. Such stress is closely linked to symptoms such as headaches, back problems, neck tension as well as gut health problems and can, in the long run, also trigger other health conditions.^[5]

Don’t worry: stressful times inevitably belong to our everyday lives, and success involves overcoming obstacles. Even though it is not realistic to live and work in a stress-free world, humans are able to control what they perceive as stressful and how to react to this.^[4]

Stress regulates our survival mode: it makes us alert and focused, sharpens our senses, makes us react quickly, run well and fight. This helped our ancestors to hunt down their prey or flee from danger. In such situations, their body secreted high cortisol levels, which made them ready to either fight or flee. In survival mode, adrenaline and cortisol flow into the body, blood pressure increases, breathing and pulse quicken and glucose is secreted for energy supply. Digestive and immune functions are stopped so that the body can focus on the situation at hand. Even today, short phases of stress can help us perform at our best when it matters.

The balance of our metabolism and of our hormones is restored by the secretion of dopamine once the dangerous situation is over. Dopamine rewards our brains for mastering the challenge.^[3]

How stress affects the body

In acutely stressful situations, signs of stress can appear in a wide variety of ways: headaches and a tense neck after a stressful day at work, a nervous stomach before an important exam, stomach aches after a family argument, a skin rash because of money worries.^[1] Stress – especially chronic stress – can also negatively affect our mental performance and memory. 

Have you already experienced your brain processing dangers so quickly that you usually don’t even notice it yourself? For example, when a car comes towards you, you jump to the side – as if automatically – and only realise afterwards what has happened.^[1]

The stress hormone cortisol also influences our immune system. High cortisol levels have immunosuppressant effects. This means that your immune system and thus your immune defence are restricted, as fewer T-cells and B lymphocytes are produced, which eliminate foreign bodies. Due to your body’s impaired defences, you are more susceptible to infections.^[7]

In medicine, however, this negative effect also has beneficial effects. Synthetically produced glucocorticoids such as prednisone are used to treat autoimmune diseases, where the immune system attacks the body’s own healthy tissue. Due to its immunosuppressant effect, the immune system’s activity is reduced which avoids further damage. In addition, it is used in allergic reactions and chronic as well as acute inflammation.^[8]

What does cortisol do?

The stress hormone cortisol is a steroid hormone and belongs to the group of glucocorticoids (the most important of which are cortisol and cortisone). When the body feels stress, more cortisol is secreted. The adrenal cortex produces cortisol and otherwise has a wide variety of functions in the body. These include, among others, its influence on carbohydrate, protein and fat metabolism, blood pressure and blood sugar. When it comes to our immune system, it also plays an important role.^[9]

The role of cortisol in the body

Cortisol is a hormone that is vital for the body. It contributes to energy metabolism, mineral metabolism and blood pressure, immune defence, processing stress, cell division and memory and brain function.^[10] Cortisol keeps us awake and alert. The function of cortisol, however, is much more widespread, as it influences many metabolic processes:

• To regulate carbohydrate, protein and lipid metabolism^[7]
• To increase blood sugar levels by transforming amino acids into glucose^[7]
• To inhibit inflammation by reducing any inflammatory factors^[7]
• To oppress the immune system by reducing the production of antibodies^[7]
• To supply the body with energy^[9]
• To release insulin^[9]

Cortisol is especially important for carbohydrate levels due to its vital function. By releasing sugar in the form of glucose, cortisol increases blood sugar levels during the night when no food is consumed so that enough energy is available to the body. If the body produced no cortisol, this would result in nocturnal hypoglycaemia, which in the worst case could lead to a coma.^[7]

Cortisol stimulates protein and lipid degradation to provide our bodies energy. Thus, cortisol speeds up the process of degrading fatty tissue and muscles.^[11]

Where is cortisol produced?

The adrenal glands are situated above the kidneys, weigh approximately five grammes and are responsible for the production of several hormones. The adrenal cortex comprises three zones:^[7]

• zona glomerulosa: production of aldosterone, responsible for the long-term regulation of blood pressure
• zona fasciculata: responsible for producing glucocorticoids
• zona reticularis: produces male and female sex hormones

Cortisol is the most important glucocorticoid which is produced in the zona fasciculata. For cortisol to be produced, cholesterol and the peptide hormone adrenocorticotropic hormone (ACTH) are needed. ACTH is secreted by the pituitary gland and activates the production of glucocorticoids in the adrenal glands. When in a stressful situation, ACTH is released.^[11]

How do cortisol levels fluctuate?

The concentration of cortisol is subject to natural fluctuations, which is typical of hormones. The concentration of the hormone depends on the time of day. Cortisol levels are highest in the morning between 6 and 9 a.m.^[7]

This is because the body is preparing for any stressful situations that might come up during the day. Over the course of the day, cortisol levels decrease and reach their low point around midnight. Cortisol is secreted in seven to ten peaks; therefore, the concentration cannot be determined by just one single sample at one point of the day.^[7]

Even though hormones are subject to natural fluctuations, certain factors can lead to low cortisol levels or high cortisol levels.

What are high cortisol levels?

What causes high cortisol levels?

High cortisol levels in the morning are pretty normal – as long as they remain within a certain range. Should, however, high cortisol levels occur throughout the day, this may be caused by the following health issues:^{[7, 12, 13]}

• Cushing’s disease
• stress
• depression
• pregnancy
• alcoholism
• birth control pills, drugs containing glucocorticoids
• obesity or anorexia
• infection
• burn injuries

Cushing’s disease leads to increased cortisol levels. These can be caused by an excessive dosage of drugs containing glucocorticoids or by tumours which produce more of the adrenocorticotropic hormone (ACTH). ACTH stimulates the adrenal cortex to produce cortisol. As soon as ACTH is released in excess, cortisol synthesis increases drastically. This results in several disorders, which are caused by excess cortisol.^[14]

Chronic stress and depression are also main causes for high cortisol levels. In stressful situations, an appropriate amount of cortisol is normally secreted to bring the body into survival mode. If you suffer from stress more often and especially high levels of stress, too much cortisol is produced.^{[8, 15]}

Due to certain instances, such as pregnancy or alcoholism, Pseudo-Cushing’s syndrome can occur. With this syndrome, elevated values do not result from natural conditions. Obesity, infection, anorexia, acute psychosis, intake of birth control pills or burn injuries can also increase cortisol levels.^{[15, 16]}

What are typical signs of stress?

Commonly observed stress symptoms include:^[17–20]

• Stomach pain, diarrhoea and other digestive problems
• Skin rash and other skin problems – for example, acne
• Headaches and back, neck and joint pain
• Palpitations and dizziness
• Tiredness, fatigue and sleep problems

In addition to these relatively immediate symptoms, there are also long-term consequences that chronic stress can trigger. The best-researched are the connections with the cardiovascular system – stress has an effect on blood pressure and pulse rate, among other things, and many studies confirm that there is an obvious connection.^[21] 

Other possible long-term consequences of long-term stress are:^[22]

• Mental illnesses such as depression, burnout, anxiety disorders
• Poor concentration and chronic fatigue
• Obesity and diabetes
• Susceptibility to infection

Besides some evidence that suggests stress is related to ringing in the ears and tinnitus, other studies additionally found that people who are under chronic stress are likely to have more upper respiratory infections, such as flu or colds. Researchers therefore suspect that stress can weaken the immune system in the long run.^[20]

In addition to the above-mentioned symptoms, high cortisol levels – that is, high stress levels, can affect the healing of wounds and how nutrients are absorbed by bones. This increases the risk of developing osteoporosis (bone loss), which may result in bone pain and fractures. Several studies also found a correlation between high cortisol levels and depression. Increased cortisol secretion leads to less fat burned – in order words, weight gain. Moreover, people with high cortisol levels may experience skin changes, high blood pressure and high blood sugar values.^[22]

In women, high cortisol levels can also lead to thicker or more visible body and facial hair (hirsutism), irregular or absent menstrual periods and in men to impotence and loss of libido and fertility.^[14]

Can stress cause stomach pain?

Symptoms in the digestive tract, such as stomach pain, constipation and diarrhoea, are particularly typical of stress. The fact that the psyche can affect the stomach probably comes as little surprise to you. You have probably experienced for yourself the sensation of butterflies in your stomach when you are nervous or anxious about exams or stage fright. 

In fact, there is a close connection between the psyche and the digestive tract – that is, the gut. It is not for nothing that we speak of the gut as the body’s second brain. Among other things, the intestines and the brain constantly communicate with each other via the vagus nerve, one of the largest nerves in the body. For example, your digestive tract can let you know when you have eaten something bad. The brain reacts by giving you nausea and a nausea stimulus to get rid of the toxins.

In recent years, it has become increasingly clear what role the gut flora or gut microbiome plays in this. The trillions of bacteria in the gut are involved in communication with the brain. Some studies have shown that chronic stress can influence the composition of the gut flora and possibly disrupt the balance between good gut bacteria such as the lactobacilli and bifidobacteria and bad bacteria.^[23] 

The good news is that you may be able to alleviate your symptoms by strengthening your gut flora. In animal studies, this has already worked: mice that were given certain lactobacilli and bifidobacteria were able to react better to stress. If this also proves true for humans, targeted probiotics, prebiotics and dietary changes could help treat stress and depression in the future.^[24]

Did you know that if you add up all the trillions of tiny organisms in your gut, they weigh about as much as your brain?^[24]

Irritable bowel syndrome: can IBS flare up due to stress?

Some studies have shown, for example, that long-term stress can increase the pain of irritable bowel syndrome (IBS) and other inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis.^{[25, 27]} In general, chronic stress seems to influence the perception of pain. People who are constantly under stress perceive more pain in conditions like IBS – in some cases, stress may even be a trigger for chronic pain syndromes.^[26]

Have you also heard that people get stomach ulcers from stress? It’s actually not that simple. Stomach ulcers are usually caused by infections with bacteria like Helicobacter pylori or by taking too many painkillers. However, stress and other lifestyle factors, such as alcohol consumption, can possibly increase the risk of ulcers and make the symptoms worse.^[28]

Are headaches caused by stress?

The link between stress and headaches has been investigated in numerous studies over the past decades. It is still not entirely clear if stress is a cause of headaches or if people who have frequent headaches perceive their stress more intensely. Needless to say, there are still many questions that remain unanswered when it comes to stress symptoms such as headaches.

In a German study with more than 5,000 test participants, for example, people had more frequent and more severe headaches the more intensely they felt stress. In the case of migraines, the connection was even clearer.^[29] Other studies also showed that stress could be a trigger for headaches and even the development of chronic headaches.^[32]

Some researchers now suspect that measures to reduce stress could also have a positive effect on people with constant headaches. For example, if you suffer from chronic headaches and you specifically watch out for stressful situations, you might be able to react better and use relaxation techniques or other measures early on.^[30]

How does stress affect your skin?

This link between stress and the appearance of our skin has also been well studied. A skin rash, for example, is a symptom often reported by people who are stressed. Stress can also be a trigger for skin diseases that occur in episodes, such as atopic dermatitis, psoriasis and rosacea.^[31] The effect of stress on the skin is already evident in adolescents – in studies, psychological stress, including exam stress, worsened the symptoms of acne in teenagers.^{[33, 34]}

Chronic stress may also be a cause of acne outbreaks in adults. This is due to the hormonal changes caused by stress. This includes the increased release of androgens. These sex hormones stimulate the hair follicles and sebaceous glands in the skin, which can cause acne outbreaks.^[35] With stress-related skin problems, it often makes sense to tackle the causes – that is, the stress and the skin problems – simultaneously, ideally with the help of a dermatologist.

Obesity and diabetes: can stress and anxiety cause diabetes?

Diabetes is a blood sugar disease, which leads to impaired insulin production and fluctuations in blood sugar levels.^[36]

Under stress, cortisol levels rise and lead to increased sugar secretion. Blood sugar levels rise.^[16] This causes the pancreas to secrete a greater amount of insulin. If the pancreas has to permanently struggle against elevated blood sugar levels, this can lead to diabetes in the long run. Due to an excess supply of insulin, the receptors that process insulin react less and less sensitively to it. This can lead to insulin resistance and type 2 diabetes.^[37]

A large-scale study with 160,000 professionals also revealed a correlation between elevated cortisol levels and obesity.^[37] However, the current study situation is still very contradictory.

It is assumed that high cortisol levels lead to changes in the fat cells. The mature fat cells (adipocytes) are produced from their precursors, the preadipocytes. In contrast to the preadipocytes, the adipocytes store fat. This can lead to weight gain.^[38]

Concerned about your blood sugar levels? Test your long-term blood sugar levels (hba1c levels) with a long-term blood sugar test. This test works by measuring your average blood sugar levels and analysing whether or not your blood glucose levels indicate early signs of diabetes. People with diabetes, after all, have too much hba1c in their blood for long periods of time.

Can low cortisol cause depression?

In the United Kingdom, 19 per cent of people claim they are depressed according to a survey conducted with 5,000 adults by the National Centre of Social Research.^[40] Furthermore, according to an article in the Pharmazeutische Zeitung (German pharmaceutical trade journal), people with depression have high cortisol levels. It is assumed that this is caused by a physiological dysfunction, which suppresses the hormones normally needed to avoid high cortisol levels.^[46]

More and more studies indicate that depression is a stress disorder, as there seems to be a strong correlation between the two. An epidemiologic study associated early negative social factors with a higher risk of developing depression. These factors included natural disasters, physical violence or sexual abuse.

Changes in one’s personal environment or negative events are another risk factor triggering depressive episodes. Depression is assumed to correlate with the secretion of the stress hormone cortisol. High cortisol levels can in the long run lead to fat deposits in the blood vessels and thus lead to arteriosclerosis. For this reason, depressed people have an increased risk of developing cardiovascular diseases.

Testing for high cortisol levels: how do I know my stress level?

A visit to the doctor is the traditional way of testing your cortisol level. However, this involves long waiting periods which causes you unnecessary stress, and results may therefore be slightly affected by this. 

Measuring cortisol is simple. These days, you can purchase an at-home cortisol test kit, which you use to measure your cortisol levels at various intervals throughout the day. These tests usually work by collecting saliva samples. Your results can then reveal the times at which your cortisol levels are high (more specifically, when your stress is highest).

The majority of cortisol in the blood is (protein)bound. Approximately one to three per cent are free. Only the free form is the active form. It is secreted into saliva and can be measured in it. As cortisol levels change when you are stressed, taking saliva samples at home is the most stress-free way to analyse your cortisol levels.^{[42, 43]}

Optimising cortisol levels: how to rebalance cortisol levels

Once you have recognised that chronic stress is the cause of many of your problems, you can try to counteract it in a targeted way. 

Stressful situations and phases cannot be avoided in life. But you can learn to react to them in a healthy way and restore mental balance in your life. One piece of advice that psychologists often give is to make sure that you do something nice at least once a day and have a little time for yourself – whether you undertake a hobby you enjoy, read a book or watch an episode of your favourite series.^[44]

Being happy makes you healthy. Researchers from Canada investigated the connection between positive feelings and the development and risk factors of cardiovascular diseases in more than 1,700 test participants over ten years. The results were as follows: less stress and more positive feelings reduced the risk of developing coronary heart disease.^[44]

What is the secret to happiness? Find out more about serotonin, the happiness hormone in our dedicated Health Portal article!

Natural stress relief: how do you relieve stress?

Apart from successful treatment or curing the underlying disease, which help to regulate stress, there are further ways to restore low cortisol levels – without drugs.^[16] 

• Give your body the chance to regenerate! Sufficient high-quality sleep helps to reduce stress. There are various sleep improvement supplements you can take these days to boost the quality of your sleep.
• Do sports! Sport helps to relieve stress and can optimise cortisol levels.
• Allow time for relaxation! Bring in those stress management techniques. You can read about these techniques in our article on emotional resilience.
• Take time to spend time with important people on a regular basis! By doing this, you activate the feel-good hormone oxytocin. It is released as a result of physical contact and lets your cortisol levels recover.

Nutrition and stress: how does diet affect stress?

Your diet alone can work wonders when it comes to fighting elevated but also low cortisol levels. We have listed some scientifically proven nutritional advice to help you manage your cortisol levels:

Treating stress: supplements to reduce cortisol

Vitamin B complex, especially vitamin B6 and folic acid, help to reduce work stress and improve your mood. Legumes, fish, walnuts, yeast and soy are rich in these vitamins.^[45]

Zinc supplements are also ideal supplements to reduce cortisol levels, as it reduces the secretion of cortisol. Oysters contain lots of zinc. Edam and Emmental cheese, as well as chicken eggs, are also ideal sources of zinc.^[50]

To find out more about foods with zinc and its health benefits, head over to our dedicated article.

Besides taking supplements to reduce cortisol such as zinc and vitamin B, you should definitely optimise your vitamin C levels. Peppers, citrus fruits and berries are rich in vitamin C, which significantly helps regulate cortisol levels. Eat them fresh, as vitamin C is easily broken down by heat and exposure to sunlight. Finally, other supplements you might take for mental balance and stress relief might include vitamin D, l-tryptophan and vitamin B12.

Low cortisol levels: what causes cortisol levels to drop?

Coffee increases your cortisol levels.^[46] If you need a caffeine boost, you should actually opt for black tea, as it is proven to lower your cortisol levels. However, please don’t drink tea if you have been advised to avoid it on medical grounds.^[47]

Fish is rich in omega-3 fatty acids, which reduce the cortisol levels in your body. This is especially the case for mackerel, herring and salmon. Some vegetable oils like rapeseed oil and soybean oil also contain larger amounts of omega-3 fatty acids.^[49]

Did you know that liquorice and one of its ingredients, glycyrrhetic acid, can actually increase cortisol levels? Pregnant women should refrain from eating liquorice, as the embryo cannot counter this influence. People who take anticoagulants should only eat liquorice in smaller quantities or better avoid it, as it contains vitamin K.^[51]

Does dark chocolate reduce cortisol?

Eating chocolate makes us happy – it is undoubtedly a hero in stressful times. Some experts have revealed that the flavonoids contained in dark chocolate, which belong to the antioxidants, inhibit the secretion of cortisol and adrenaline. 

In 2014 a study investigated the effects of dark chocolate on cortisol levels. One half of study participants ate half a bar of chocolate and the other half, the placebo group, ate chocolate without flavonoids. Afterwards, they all had to pass a stress test.^[52] For the participants that ate dark chocolate, the levels of the stress hormones cortisol and adrenaline increased at a slower rate. Thus, the higher the flavonoid blood levels, the smaller the increase of stress hormones.^[52]

Due to their chemical bond, antioxidants can slow down or even stop the oxidation of other substances. Antioxidants can be found in their natural form, but due to their positive health effects, they are increasingly synthetically made. The most well-known antioxidants are vitamin C, vitamin E, micronutrients such as zinc and selenium, carotenoids and beta-carotene.^[53]

To find out more about the health benefits of chocolate, head over to our Health Portal article.

How do you relieve stress quickly?

For some, drinking a cup of tea and reading a book already helps to come to rest. For others, a punching bag or other sports help to relax. All of these have in common that they improve our perception of stress, but they don’t tackle the source of high cortisol levels in the long run. Certain targeted relaxation techniques, often paired with exercise, have been shown to lower stress levels. This has a positive influence on not only your mind but also physiological factors such as your blood pressure, pulse and breathing rate.

These relaxation techniques include yoga, tai chi, autogenic training and progressive muscle relaxation, but also other types of meditation and mindfulness training. Some of these techniques are easy and quick to learn – for example via online videos. Others need some practice and coaching, but the good news is that most people can benefit from them after a short time.

Studies furthermore reveal that regular physical activity can reduce stress and lower the risk of depression and anxiety. At the same time, exercise improves your cardiovascular health and thus counteracts possible long-term consequences of chronic stress.^[54]

How does socialising help mental health?

Our social environment is crucial to how we experience stress. Studies have repeatedly shown that people who receive a lot of support from friends and acquaintances, family, partners and colleagues are better able to react to stress and crises.^{[55, 56]}.

When you are under stress and pressure at work, it can help, for example, to meet colleagues regularly for a chat and to let off a little steam about the job. This also works if you are working from home. Just meet up for a digital coffee break via video call every now and then.

In any case, research shows for people of all ages that when we feel supported by people around us, well-being and general physical and mental health increase.^[57]

How to lower cortisol levels through medication

Medication is only used if cortisol is needed permanently – that is, over a lifetime – and no other form of treatment can help like, for example, in people with Addison’s disease or Cushing’s disease. For a long time, the drugs metyrapone, aminoglutehimide, mifepriston and ketoconazole have been used. They lower cortisol levels by inhibiting the enzyme needed for the synthesis of steroids.^{[58, 59]}

What are signs of stress – at a glance

Why do high cortisol levels make you ill?

Stress is your body’s reaction to situations that it perceives as a threat. It releases the stress hormones adrenaline and cortisol, thereby increasing blood pressure, pulse and breathing rate, among other things. With chronic stress, the stress hormone levels are also constantly elevated. This upsets the body’s functions, affecting the cardiovascular system, digestion and psyche in particular.

What are the common signs of chronic stress?

Signs of chronic stress occur all over the body. Acute symptoms include digestive problems such as stomach pain and diarrhoea, skin rashes and acne, headaches, back pain as well as exhaustion and sleep problems.

Possible long-term consequences of chronic stress are an increased risk of cardiovascular diseases, obesity, type 2 diabetes and poor concentration. Mental illnesses such as depression and anxiety disorders can also occur.

What can I do about stress symptoms?

Some consequences of stress should be treated by a doctor – for example, high blood pressure, depression and chronic skin changes.

Otherwise, it is of course worthwhile counteracting stress as the cause of the symptoms. You should therefore introduce stress management techniques in your everyday life, such as relaxation techniques, physical activity and socialising.

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