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Stress hormones: what they are and what they do in the body

Themes :
behaviour hormones
Published on 9 October 2023

We all know what stress feels like. You may be stuck in traffic trying to get to an important appointment, dealing with a sick child or relative, or trying to cope with a looming deadline at work. You feel anxious, tense, and hyperalert. Your blood pressure levels rise and your heart beats faster. You may become flushed or sweaty. You’re stressed!

Stress is your body’s way of dealing with any situation that it classifies as a threat. It’s a natural response to danger that humans developed to keep us safe. Anytime you feel under pressure, are in a heightened emotional state, or are worried about something, your body goes into a stress response.

During the stress response, the body releases various types of hormones. Stress hormones put the body into a ‘fight or flight’ mode to get us ready to physically deal with the threat we’re facing. While this response can help us to act and deal with difficult situations, it can also cause health problems. Chronic stress and the constant release of stress hormones can negatively impact our physical and mental health.

Exactly what hormones are released during stress? Can we reduce stress hormones and lessen their impact on our health? We delve into these questions and explain what stress hormones are, what they do to your body, and what you can do to control them.

What Are Stress Hormones and What Do They Do?

A complex chain of events happens in the body whenever we are confronted by a stressful situation. The stress response starts in the brain. The part of our brains that deals with emotional responses, the amygdala, reacts to stress by sending a distress signal to the command centre of the brain, the hypothalamus.

Our hypothalamus sets off the sympathetic nervous system by sending signals to our adrenal glands via our autonomic nerves. The adrenal glands do their part by flooding our system with stress hormones. After the first intense burst of hormones, the hypothalamus then sends out another dose of stress hormones to keep us in a state of readiness.1

When the threat has passed, our bodies slow the flow of stress hormones, and we gradually return to normal. The stress response happens in an unbelievably short amount of time, almost instantaneously when a sudden threat arises. Often, the stress response activates before our brains can fully process visual stimuli. This helps us to react right away when faced with a threat, such as an oncoming car, for instance.

The stress hormones that are released into our bodies act to spike our adrenalin levels, raise our heart rates, increase our blood pressure, raise blood sugar levels, oxygenate our blood, invigorate our muscles, and dilate our pupils. Our brain is put into a hyper-vigilant state and the body directs blood away from non-essential tasks toward our muscles. We become fully primed to either attack the threat or flee from it.

What Are the Three Main Types of Stress Hormones?

There are three main types of hormones released by our bodies when we enter a stress response:

  • Cortisol
  • Catecholamines
  • Vasopressin

We’ll now take a look at each of these hormones in detail to see how they help us deal with pressure and what symptoms they cause.



Cortisol is perhaps the most well-known of the three main classes of stress hormones. It is classified as a steroidal glucocorticoid hormone and is produced by the adrenal glands. Cortisol has a range of effects on the body. During the stress response, cortisol is not released in sharp bursts all at once. Rather, the body releases slow and steady small amounts of cortisol over a longer period.

Cortisol is the main stress hormone and helps to keep our bodies and minds primed to deal with long-term stressful situations. Cortisol acts to suppress non-essential functionss in the body, like our digestive systems, our reproductive systems, and our immune systems. The body can instead direct its resources to managing the stressful event.2



Catecholamines are a group of stress hormones that includes epinephrine (also known as adrenalin), norepinephrine (known as noradrenaline), and dopamine (the so-called ‘feel good’ hormone). Catecholamines act as neurotransmitters and transmit signals to nerve cells throughout the body during the stress response.3

  • Epinephrine is the main driver behind the fight-or-flight response. Colloquially known as adrenalin, epinephrine raises our heart rate and blood pressure levels. It promotes blood flow to the muscles and boosts our energy levels. Our bodies release large surges of epinephrine during the early stages of the stress response.4
  • Norepinephrine is a similar type of hormone to epinephrine. Released slowly during stressful situations, norepinephrine acts to enhance our alertness and vigilance.5
  • Dopamine controls how our moods and helps us to feel motivated and experience pleasure. When we do something that feels good to us, our bodies are flooded with dopamine. The role of dopamine in the stress response is still not well understood, but it plays a key role in helping us to manage rapidly changing environments.6



Vasopressin plays a major role in regulating our blood pressure and how we metabolise water. It is produced by the hypothalamus and stored by the body in the pituitary gland just beneath the brain. Whenever we experience a stressful situation or a strong emotion, the body releases vasopressin into our bloodstream. Vasopressin boosts our blood pressure and helps our kidneys to reabsorb water from urine. This helps our muscles to be ready to react quickly and stops us from becoming dehydrated during physical exertion.7

What Are the Health Effects of Stress on the Body?

The stress response is highly useful when we are in a life-threatening situation or need to take action quickly. Unfortunately, chronic amounts of stress can cause a wide range of issues. Too much stress lowers our immune systems and makes us more vulnerable to developing certain diseases.

When we experience chronic stress, the body has various reactions to the continued amounts of hormones. Continuously high levels of cortisol can increase weight gain, increase blood pressure, decrease bone density and lead to diseases such as Cushing syndrome, according to a study by the Mayo Clinic. 8 High levels of cortisol can also cause dry skin and brittle hair.

Chronic stress can lead to several serious health conditions and diseases. Stress causes an increased risk of heart disease due to continued high blood pressure and irregular heart rhythms. During the stress response, our blood vessels constrict. This can cause plaque to build up and cause blockages which increases the risk of stroke.

Chronic stress also interferes with the connection between gut microbiota and the brain. This can cause gastrointestinal problems.

Since stress hormones divert resources from the immune system, chronic stress can dramatically weaken the immune system. A weakened immune system leaves our bodies vulnerable to attack from viruses and diseases. A depleted immune system can also increase our risk of developing certain cancers, make us more susceptible to developing diabetes, accelerate tumour growth, and exacerbate existing medical conditions.

What Are the Psychological Effects of Stress?

As well as the physical impacts of chronic stress, there are also several psychological effects. Medical researchers from the Mayo Clinic have found that chronic stress leads to increased feelings of anxiety and depression. Chronic stress can cause cognitive issues such as problems with memory and brain fog.9

Chronic stress is a major contributor to sleep issues. A continual flow of stress hormones keeps our bodies in a constant state of tenseness and readiness leading to severe insomnia. It is thought that chronic stress also plays a major role in Chronic Fatigue Syndrome (CFS).

How to Reduce Stress Hormones in Your Body

There are several fairly simple techniques and lifestyle changes that can help to lower the levels of stress hormones in the body. Changing to a healthier diet with more whole grains, vegetables, fruits, lean protein, and beneficial fats can help to balance hormone levels.

Regular exercise relieves tension and helps to elevate our moods. It also slows down the rate of cortisol production in our bodies. People with regular exercise routines suffer from lower levels of stress than those who do not exercise frequently.

Relaxation techniques like breathing exercises, yoga, Tai Chi, or meditation can greatly reduce the amount of stress hormones in our bodies. These methods help us to feel calmer and lower the production of stress hormones. Getting enough sleep is also vital in managing the levels of stress hormones in your body.

It is strongly recommended to avoid unhealthy ways of coping with stress such as consuming too much alcohol, overeating, or drug abuse.


The hormones released into our bodies during the stress response play crucial roles in keeping us safe from harm. Chronic stress, however, is a condition that should be avoided. When the body is overloaded with stress hormones for long amounts of time, we can develop various mental health problems and physical issues. Managing the levels of stress hormones in your body will enhance your overall health.

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1 PubMed: DOI:  10.038/nn.4086
2 PubMed:
3 PubMed:
4 PubMed:
5 PubMed:
6 PubMed: DOI: 10.1038/s12276-020-00532-4
7 PubMed: