All you need to know about the stress hormones

Have you ever felt like your brain has 100 tabs loading, your jaw just won’t unclench, and even replying to a WhatsApp message feels like too much?

Modern life can be hectic, and while your body has evolved a brilliant system for reacting to stress – it maybe wasn’t designed to be used all day, every day. This ancient response, designed to protect you from danger and help you quickly adapt to the situation at hand is formed by three hormones – adrenaline, noradrenaline, and cortisol.

The article explains what they do, and how you can use this to manage stress.

We’ll cover:

• What is adrenaline?
• Long-term effects of too much adrenaline
• What is noradrenaline?
• Symptoms of noradrenaline overload
• What is cortisol?
• Effects of raised cortisol
• What is fight or flight mode?

 

What are the three main stress hormones?
 

There are three hormones involved in your stress response. They’re produced by your adrenal glands (which are found just above your kidneys), whose job it is to maintain your blood pressure and metabolism.

The hormones are:

• Adrenaline
• Noradrenaline
• Cortisol

You can read more about the adrenal glands in our blog, but let’s take a closer look at each hormone.

1. What is adrenaline?
 

Have you ever been woken from sleep by a loud or unfamiliar noise? You suddenly have a surge of energy, all your senses are on high alert, your muscles are tense, your heart is pounding, your hearing and vision sharpened. You are ready to flee or fight. That immediate reaction is all thanks to adrenaline.

Adrenaline is a hormone and neurotransmitter which is secreted into the blood stream to act on other cells in the body. Its job is to prepare your body to respond to a threat.

Adrenaline can:

• Increase your heart and breathing rate
• Increase blood flow to your muscles
• Make you feel more alert and energised
• Help release stored energy

This is useful in times of danger – perhaps less useful when meeting tight deadlines or worrying about an awkward conversation.

What are the long-term effects of too much adrenaline?

Adrenaline is supposed to give you a short-term boost, but if your stress levels are higher all day, what happens if your adrenaline response is triggered too often?

You might notice symptoms such as:

• Sweaty palms
• Racing heart
• Shakiness
• Headaches
• Difficulty relaxing

This can contribute to that ‘wired but tired’ feeling, struggling to concentrate on tasks, or switch off after work. Adrenaline isn’t the only cause for this though, and if this is relatable, it could be a good idea to investigate with your doctor.

How to 'hack' your adrenaline

There's a few techniques you can try to get your adrenaline levels to settle a bit.

Adrenaline lowering tips include:

• Breathe out for longer than you breathe in. Breathing in for four seconds then slowly out for eight seconds for a few minutes can help.
• Move your body to release the energy. Try doing jumping jacks, climbing stairs, or walking quickly before and after an anxiety-inducing task.
• Keep an eye on your caffeine intake.

2. What is noradrenaline
 

Noradrenaline is a team-mate to adrenaline. It’s a hormone and neurotransmitter too, and acts as a chemical messenger.

Noradrenaline can:

• Heighten your focus
• Improve your responsiveness
• Improve blood flow to essential organs
• Divert blood flow from non-essential functions (during the stress response)

What are symptoms of noradrenaline overload?

As with adrenaline, noradrenaline is incredibly useful in the right situation. But an overactive stress response can leave you feeling tense or restless.

Common symptoms include:

• Overthinking
• Struggling to relax
• Anticipation of doom

As noradrenaline also regulates your blood pressure, certain medical conditions or unusually high levels can be associated with raised blood pressure, headaches, and a pounding heartbeat. If this feels relatable, it’s important to seek medical advice.

How to 'hack' your noradrenaline

While it's important to have noradrenaline to sharpen your focus, if it's in overdrive it can feel like your mind is racing.

Tips to keep your noradrenaline in check:

• Avoid multitasking. Try turning off your notifications, only working on one device at a once, and allowing time to sink into each task.
• Take breaks away from your screen, outside if possible.
• Brain dumping – writing down all your thoughts on paper can help your mind let go of worries. You can do this in the evening or in the morning (or both).

3. What is cortisol
 

Cortisol is essential for your body – but it often gets a bad reputation as the stress hormone.

Cortisol has many roles including regulation of your:

• Blood sugar levels
• Metabolism
• Blood pressure
• Inflammation

While adrenaline is released quickly, cortisol is more of a slow burner. It follows a daily rhythm, rising and falling throughout the day.

In terms of your response to stress, once your adrenaline release starts to slow down, cortisol is released.

What are the effects of too much cortisol?

The perfect amount of cortisol can be lifesaving when in survival mode. Short term, cortisol can help to develop resilience and perform well in challenging situations.

However, these days, stress is more of a way of life for many people.

When your body is in a constant state of stress, the sympathetic nervous system is continually activated. Continual high levels of cortisol levels can lead to an increased risk of serious health implications over time.

Chronic stress with raised cortisol levels can lead to:

• A reduced immune function
• Higher blood pressure
• Anxiety
• Depression
• Digestive problems
• Insomnia

High levels of cortisol can also cause fat to be stored around the organs in the abdomen (visceral fat), which increases the risk of cardiovascular disease and diabetes [7].

How to 'hack' your cortisol

Your cortisol levels fluctuate throughout the day, and there's a few things you can do to support the natural rhythm.

Cortisol-lowering tips include:

• Try to keep your bedtime and waketime regular.
• Avoid screens in the evening or use a blue light filter or nightshift mode where possible.
• Get out in daylight as early as you can.

What is fight or flight mode, and how do I get my body out of it?
 

Imagine you're about to give a big presentation. Your brain recognises a potential threat, activates your stress response, and signals to your adrenal glands that it’s time to release adrenaline and noradrenaline. Your heart beats faster, your attention sharpens and your body prepares for action.

This is known as fight of flight mode.

If the pressure continues, your brain also activates the hypothalamic-pituitary-adrenal (HPA) axis, a communication pathway that helps regulate cortisol release.

Once the challenge passes, your body can gradually return towards its resting state.

This is great in theory, but the trouble is that modern stressors don't always have a clear finish line.

Money worries, family pressures, and constant phone notifications (to name a few) can repeatedly trigger feelings of threat or urgency. You might finish one stressful task only to move straight into the next.

Over time, these ongoing stressors can affect everything from your sleep and mood to concentration and digestion.

So, how do you switch it off?

You can't simply tell your body to stop feeling stressed, but you can lower your stress levels.

Try these tips to reduce your stress:

• Have a hot drink – it's thought that the warmth of tea may trigger your parasympathetic nervous response (basically the opposite of your stress response) and signal that it's safe to relax.
• Slow your breathing – try a mindfulness app like Headspace or Calm to help you learn how to breathe your way to calm.
• Take a digital break – put your phone on Do Not Disturb, have screen-free nights, delete busy apps or try an app blocker and see how long you can go for without using your phone.
• Get some fresh air – as little as five minutes outside can help to calm your nervous system (bonus points if you leave your phone behind!).
• Write it out – jotting down tasks you've completed and things still to do can remove the urgency of your day-to-day life. 

Don't be disheartened if you don't find these tips work immediately – reducing stress takes time and patience. If you find your anxiety or stress is too overwhelming, there is always help. Reach out to your GP who can talk through what you're experiencing, or if you need to talk to someone immediately you can contact Samaritans on 116123.

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References

1. Ranabir, S. and Reetu, K., 2011. Stress and hormones. Indian Journal of Endocrinology and Metabolism, 15(1), p.18.
2. Alshak, M.N. and Das, J.M., 2021. Neuroanatomy, Sympathetic Nervous System. In: StatPearls. Treasure Island (FL): StatPearls Publishing.
3. Tindle, J. and Tadi, P., 2020. Neuroanatomy, Parasympathetic Nervous System. In: StatPearls. Treasure Island (FL): StatPearls Publishing.
4. Zaccaro, A., Piarulli, A., Laurino, M., Garbella, E., Menicucci, D., Neri, B. and Gemignani, A., 2018. How breath-control can change your life: a systematic review on psycho-physiological correlates of slow breathing. Frontiers in Human Neuroscience, 12, p.353.
5. Ensari, I., Greenlee, T.A., Motl, R.W. and Petruzzello, S.J., 2015. Meta-analysis of acute exercise effects on state anxiety: an update of randomized controlled trials over the past 25 years. Depression and Anxiety, 32(8), pp.624–634.
6. Quinlan, P., Lane, J. and Aspinall, L., 1997. Effects of hot tea, coffee and water ingestion on physiological responses and mood: the role of caffeine, water and beverage type. Psychopharmacology, 134(2), pp.164–173.
7. Mark, G., Gudith, D. and Klocke, U., 2008. The cost of interrupted work: more speed and stress. Proceedings of the SIGCHI Conference on Human Factors in Computing Systems (CHI 2008), pp.107–110.
8. Scullin, M.K., Krueger, M.L., Ballard, H.K., Pruett, N. and Bliwise, D.L., 2018. The effects of bedtime writing on difficulty falling asleep: a polysomnographic study comparing to-do lists and completed activity lists. Journal of Experimental Psychology: General, 147(1), pp.139–146.
9. Albulescu, P., Macsinga, I., Rusu, A., Sulea, C., Bodnaru, A. and Tulbure, B.T., 2022. 'Give me a break!' A systematic review and meta-analysis on the efficacy of micro-breaks for increasing well-being and performance. PLOS ONE, 17(8), e0272460.
10. Thau, L., Gandhi, J. and Sharma, S., 2025. Physiology, Cortisol. In: StatPearls. Treasure Island (FL): StatPearls Publishing.
11. Harvard Health Publishing, 2021. Stress and the sensitive gut. [online] [Accessed DATE].
12. van der Valk, E.S., Savas, M. and van Rossum, E.F.C., 2018. Stress and obesity: are there more susceptible individuals?Current Obesity Reports, 7(2), pp.193–203.
13. Scheer, F.A. and Buijs, R.M., 1999. Light affects morning salivary cortisol in humans. Journal of Clinical Endocrinology & Metabolism, 84(9), pp.3395–3398.
14. Bei, B., Seeman, T.E., Carroll, J.E. and Wiley, J.F., 2017. Sleep and physiological dysregulation: a closer look at sleep intraindividual variability. Sleep, 40(9), zsx109.
15. Ebrahim, I.O., Shapiro, C.M., Williams, A.J. and Fenwick, P.B., 2013. Alcohol and sleep I: effects on normal sleep. Alcoholism: Clinical and Experimental Research, 37(4), pp.539–549.
16. Hill, E.E., Zack, E., Battaglini, C., Viru, M., Viru, A. and Hackney, A.C., 2008. Exercise and circulating cortisol levels: the intensity threshold effect. Journal of Endocrinological Investigation, 31(7), pp.587–591.
17. Waxenbaum, J.A., Reddy, V. and Varacallo, M., 2021. Anatomy, Autonomic Nervous System. In: StatPearls. Treasure Island (FL): StatPearls Publishing.
18. Society for Endocrinology, 2021. Adrenocorticotropic hormone. You and Your Hormones. [online].