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Cortisol And Stress – What’s The Connection?

Author: Forth

February 24, 2021

Reviewed by: Dr Thom Phillips

Mental health

Man sat in a chair looking stressed

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Cortisol: The Stress Hormone

Cortisol is often referred to as the ‘stress’ hormone as it is released by the body when we go into ‘fight or flight’ mode, but it actually plays a key role in our body as it is involved in a number of metabolic and immune processes.

Cortisol is a steroid hormone which breaks down fat and protein, as well as stimulating the production of glucose by the liver. 

In line with a normal circadian rhythm, cortisol levels are highest first thing in the morning and gradually decline throughout the day. However, our cortisol levels can become unbalanced if, for example, we have a poor, irregular sleep pattern which means the normal rise and fall of cortisol levels are disrupted. 

Prolonged stress can also result in a loss of variation in cortisol levels throughout the day and result in consistently high levels.

So, what happens when we become stressed? Let’s take a look.

What Happens When We Are Stressed?

When we become stressed, for example, when we have to present, have too much work on, or we are scared of a particular situation; our bodies go into fight or flight mode.

When we are stressed, what is known as the HPA axis (hypothalamus, pituitary gland and adrenal gland) coordinate our body’s response to stress. The hypothalamus is the brain’s command centre and stimulates our autonomic nervous system which in turn triggers the adrenal gland to release adrenaline. To sustain this response, the pituitary gland releases a hormone called adrenocorticotropic which causes the adrenal gland to release cortisol. This prepares the body for ‘fight or flight’ causing our heart rate to increase, our breathing to speed up and gears our muscles up to take action – to fight or to run.

This response is good when we need it, it can actually give us the adrenaline rush we need to get through that presentation, or job interview. But it becomes a problem when the stress is sustained over a long period of time.

Man sat at a desk with his head in his hands

What Causes Stress

Everyone experiences stress differently and what may be a cause of stress for one person isn’t for another. For example, some people love presenting to a crowd of people, while others couldn’t think of anything worse. Some of the common causes of stress include:

  • Job/career
  • Finances
  • Family issues
  • Poor health or poor health of a loved one
  • Moving house
  • Divorce
  • Bereavement
  • Busy daily commute
  • Fear of crime
  • Problem neighbours

It’s important to understand the different types and signs of stress, you can then begin to identify what your own, personal stress triggers are and ways to reduce them.

What Are The Different Types Of Stress?

There are 3 main categories of stress:

  1. Acute Stress
  2. Episodic Acute Stress
  3. Chronic Stress

Acute stress is when the body responds to an unexpected event or an upcoming challenge. It’s often short lived and is the most common type of stress.

Episodic Acute Stress is acute stress experienced on a more frequent basis; this can manifest itself in the feeling of always being under pressure.

Chronic stress is caused by ongoing emotional pressure such as a stressful job or family situation. When you experience chronic stress, the body is experiencing stress far too frequently. This means the body hasn’t time to recover between episodes, resulting in prolonged elevated cortisol levels.

What Are The Signs Of Stress?

If we are under prolonged stress and our bodies are in constant fight or flight mode, it can cause our cortisol levels to remain high throughout the day. This will result in a number of changes to our physical as well as mental state.

According to Mind, these are some of the signs that you may be stressed:

  • You feel irritable or aggressive
  • You feel wound up and impatient
  • You struggle to focus and concentrate
  • You feel overwhelmed and unable to cope
  • You may feel anxious or afraid
  • You are unable to enjoy yourself and may even feel depressed
  • You may experience trouble getting to sleep or staying asleep
  • Your mind may race all the time and you find it difficult to switch off

Some of the physical and mental symptoms of stress included:

  • Chest pain or feeling like you have a tight chest
  • Raised blood pressure
  • Headaches, dizziness or shaking
  • Tight muscles, aches, and pains
  • Tight jaw
  • Stomach or digestive problems
  • Exhaustion
  • Weakened immune system
  • Anxiety, depression, panic attacks

All of this is due to prolonged high cortisol levels and your body being in a constant state of ‘fight or flight’.

Some people may try to cope with stress by over eating, and eating food that is high in fat or sugar, drinking too much, smoking or taking drugs. All of which put extra stress on the body. So, what are the more effective ways to reduce stress levels.

How To Reduce Stress And High Cortisol Levels

If you think you may be suffering from episodic or chronic stress, then the first step is to see your GP and discuss the causes of your stress. They will then be able to suggest the best course of action which may include talking therapies or ways to help you manage stress better.

If you suffer from acute stress, then ensuring you give your body time to recover is important in reducing your cortisol levels. Some of the things you can do to relieve stress include:

  • Exercising – helps to release endorphins which will help improve your mood. Walking in nature is also good for relieving the feelings of stress. Exercise also helps improve sleep quality as well as getting rid of any excess energy as a result of adrenaline.
  • Talking – simply talking to someone you trust can help reduce stress levels helping to offload worrying thoughts.
  • Reduce Caffeine – it can be tempting to drink more coffee when stress impacts your sleep, but this will only compound the problem.
  • Reduce Alcohol – alcohol can help you feel relaxed after a stressful day, but it changes the levels of serotonin in your brain and increases any feelings of anxiety. It can also impact your sleep, making it harder to cope the next day due to a poor night’s rest. 
  • People – spend time with friends and family, particularly if you are dealing with a stressful situation on your own. Being around people can lift your spirits and help reduce your stress levels.
  • Yoga and mediation – are great ways to slow a racing mind. Learning to live more in the present rather than worrying about the past or future will help relieve feelings of stress.
  • Breathing – breathing exercise, such as the 4-4-8 method (breath in for the count of 4, hold for 4, breathe out for 8) are great for triggering the parasympathetic nervous system which calms the body down and aids rest.
  • Eat well – nutrition plays a huge part in both our physical and mental wellbeing. Ensuring you have a healthy balance diet will help support your body during stressful times.
  • Stay hydrated – it can be easy for your body to become dehydrated if you are drinking a lot of coffee and stress makes you perspire a lot. Staying hydrated will help lessen the stress on your body.
Woman meditating


Cortisol plays a key role in our bodies, and short periods of stress can help us perform when we need it. But periods of prolonged stress can cause our cortisol levels to stay high, having a negative impact on both our physical and mental wellbeing.

If you are concerned that you or someone you know is suffering from stress, reach out to your GP or get support from mental health charities.


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This article was written by Forth

This information has been medically reviewed by Dr Thom Phillips

Thom works in NHS general practice and has a decade of experience working in both male and female elite sport. He has a background in exercise physiology and has published research into fatigue biomarkers.

Dr Thom Phillips

Dr Thom Phillips

Head of Clinical Services