How Stress Affects Your Digestion

Today I’m finally sitting down to tackle the topic I’ve wanted to write about for absolutely ages: stress. We all know that stress can impact our digestion- whether it’s the day before we jet off on our holidays or a tough exam. However, what about long-term stress? Many of us can pinpoint flare ups with periods of stress but why is that the case? Is it because we slip into bad habits: poor sleep, rubbish food choices, not giving our body the rest it craves? Or is it more than that?

My desire to write this post began in October 2016, when on the final part of my nutrition course we went over the stress cycle.Now, I had been studying nutrition for two years at this point but it was only sat in front of a tutor that the whole process hit home- and for me, I started to realise how much stress I had been putting myself under and how I needed to take action. Since then, I’ve blogged about changing jobs, trying counseling and this week I started acupuncture (blog coming soon on my experiences!). However, learning about how stress affected the body really helped me in my ongoing bid to tackle it- so I thought I would share what I have learned in the hope to help others. The key hormone involved in this in cortisol- so If you stay with me to the end of this post (I promise, you’ll learn loads) you’ll see I have teamed up with Cerascreen (a home testing company) to give my readers the chance to win a cortisol testing kit and a histamine test-which can be a really useful kit in figuring out if stress is causing problems with your digestion and the rest of your body. 

How Does Stress Affect Your Body? A Step by Step Guide

1.When we’re stressed, you’ll know that our body goes into fight and flight mode. But did you know that it does this by raising our blood pressure, which gets our heart pumping?

2. Because of this, the sodium in our body rises and it can cause our to lose magnesium (I mentioned why many of those with digestive issues are often deficient in magnesium in my supplements for digestive health post) Sodium also causes water to leave the body so it’s likely you’ll become dehydrated.

3.Cortisol is then increased. Now, cortisol is a steroid hormone that is vital for many functions in the body but it also helps increase insulin– this means we have more glucose in our blood to deal with the stress- hence why during times of stress we may have temporary bouts of energy followed by extreme tiredness. This is all to do with our blood sugar (and erratic blood sugar levels can be linked to fatigue- I explain ways to combat this in my fatigue post ).  As you can imagine, if we keep getting stressed, we’ll keep increasing our cortisol until eventually, we’re not able to sustain those levels.

This can then lead to adrenal fatigue as our adrenal glands are exhausted and therefore they can no longer regulate the amount of cortisol they produce- this can lead to extremely high or (mostly in the later stages of adrenal fatigue) extremely low levels of cortisol. This graph is really effective at showing how this works.


As you can see, our cortisol varies throughout the day. This makes it a tricky hormone to test for but if you suspect you might have adrenal fatigue here are some symptoms….

I will be giving away a Cerascreen cortisol test at the end of this post- it tests your cortisol levels throughout the day, so you can identify a pattern- it’s really useful in diagnosing adrenal fatigue but also whether your cortisol patterns are normal.

Just before we move on from cortisol, it’s important to differentiate between adrenal fatigue and Addison’s disease (more info from the NHS here) Interestingly, several of you on facebook told me you had been diagnosed with this after repeated steroid use so it is well worth learning about.


4.Now we’ve chatted about cortisol, let’s see what happens next. Well, our body releases IL1, IL6 AND TNFA. To simplify a lot, these are the cause of inflammation(some of us with IBD will be on ‘anti-TNF’ which helps with blocking the TNF action).

5.Our nervous system can then start to shut down other systems to prioritise the stress it’s dealing with. It can shut down our digestion or even our reproduction. This explains why our periods might be late or even infertility can occur during stressful periods.

6.There can be raised levels of histamine in the body- this is linked to cortisol and our bodies increasing histamines during stressful periods. On my course, we read a fascinating case study of an athlete who suddenly became allergic to latex during a stressful period! And another who suddenly developed severe hay fever after surgery. Fascinating isn’t it? Interestingly, those who are stressed often struggle with stomach acid and are put on PPI medication by their doctor- which also causing histamines to increase! They may then notice random allergies to things like fruit, that they hadn’t experienced before.

What about the digestive system?

At this point, the nervous system might decide to shut down the digestive system to prioritise other parts of the body. If our digestive system diverts energy away from our digestive system, the following can happen….

  • our gut suppresses hydrochloric acid; causing low stomach acid and possibly an overgrowth of bacteria.
  • our gut decreases absorption of iron and calcium.
  • our gut decreases the production of an intrinsic factor of B12 absorption leading to deficiency.
  • our gut struggles to break down protein so you might see food in your poo!
  • It can also alter our gut bacteria- which is linked to both inflammatory bowel disease and other digestive disorders.

What can I do to stop this cycle?

The cycle I’ve outlined can seem really scary and sometimes stress can be out of our control. If you are in the early stages of dealing with stress, then I have popped some very straightforward tips below that help me. If you suspect you are suffering from adrenal fatigue in particular, then it is a complicated process and not one I can cover in a blog post, But obvious, y speak to your doctor (although I have heard there is not much recognition of this on the NHS).

  • Cognitive behavioral therapy can be useful if your stress centers around thought patterns (I’ve blogged about my experiences of it here.)
  • Getting enough sleep can be crucial.
  • Looking into your cortisol levels using a stress hormone test (like this one I’m giving away below)
  • Make sure you look at protein based breakfasts which will help stabilise blood sugar levels. Try my turmeric protein smoothie.
  • Try to eat little and often when stressed.
  • Try to keep hydrated when stressed!
  • Meditation can be really useful- I use HeadSpace and Calm apps (both available on in the app store)
  • Yoga can help. Read my yoga for digestion post for lots of tips and info on free classes.

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Giveaway time

If you’ve stayed with me up until the end of this post then you definitely deserve rewarding. One lucky winner will receive a stress hormone cortisol test and an antihistamine test (worth a total of £129.98!) Enter via the Rafflecopter box below…

Stress Hormone Test (Cortisol) Stress Hormone Test (Cortisol)

Histamine Intolerance TestHistamine Intolerance Test






a Rafflecopter giveaway




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  1. Sharon Leighton
    July 24, 2017 / 9:24 am

    Interesting post, as always, Jenna.

    I’m sure my experience mirrors that of many others: extreme stress increases the likelihood of increased IBD activity. And sustained periods –> flare.

    Meditation has been proven to increase the parasympathetic nervous system so counteracting the stress response. But I bet you know this 😉

    I’ve completely changed my lifestyle but found mindfulness courses to really help as you learn meditation + relaxation + a movement component. The 3 together are synergistic. Can’t find a course? Then you can do the parts alone. Plus learning in a group helps amplify the effect & you have a support group around you.

    digestive system diverts energy away from our digestive system
    Should be nervous system diverts energy away from our digestive system

  2. July 26, 2017 / 7:50 pm

    I never even knew these tests existed, what a great insight to have about how well or not so well our bodies are working. I struggle with IBS and have done since I was 2 years old! But they never really did other tests to eliminate other causes. I know certain foods don’t help, but my stress/anxiety is the main trigger. I’ve had CBT courses, but I find meditation, massages and baths help alot, especially when using aromatherapy associates oils 🙂

  3. Anneka Avery
    August 10, 2017 / 1:56 am

    I’m almost crying as I read through this blog post. I am absolutely convinced I have adrenal fatigue but am struggling to get a diagnosis and am show all symptoms! The problem I have is I am already diagnosed with fibromyalgia so the doctors believe it is simply that. I wish I could know he answers to why my health is so bad! I’m keeping an eye on your blog in hope it may help thanks again!

    • Jessica
      October 12, 2018 / 1:48 am

      Ask the doctors to test cortisol levels. If they are low ask for an ACTH stimulantion test I was diagnosed with adrenal suppression from this. Best of luck

  4. Carly Belsey
    August 17, 2017 / 6:39 pm

    This is so interesting, I never thought you could buy anything like this. I feel like I have every single one of the symptoms! I really need to sort my life out! Thank you

  5. September 6, 2017 / 11:50 am

    Thanks for sharing this it was very interesting and put a lot of light on what stress can cause in our bodies.

    Great post

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