Can stress be making you sick?

A woman looking pained

I have a confession – I am writing this with a fair dose of self-interest. It’s been a difficult few months in our family with a fair bit of stress and worry. So, I have found it interesting to remind myself of the different ways our bodies, and minds, can respond to stress. I wanted to share this with you though, because I see these responses in so many of my clients. Yet so few have a good understanding of the physical implications of their emotional stress.

You have probably heard of the “fight or flight” response to danger - the automatic survival response, controlled by the sympathetic nervous system. It conjures up images of cavemen running away from sabre-toothed tigers, doesn’t it? These days, we don’t commonly need to run away from tigers, but we would all still be familiar with the same response this elicits – maybe with a “near miss” accident, or when we feel unsafe walking home at night. Your heart races, you feel sweaty, your pupils dilate, and blood gets directed to major muscles so they are primed, tense and ready to help you run away from a potential attack.

What many people don’t realise is that we get exactly the same “danger” response with emotional threats as we do with physical ones. As far as our brain is concerned, there really is very little difference between these things. Emotional threats - including life stresses (moving house, losing your job, work stresses), worry, fear and even grief - all provoke the same sympathetic nervous system response that we get when running away from a tiger, to different degrees. All threats trigger the release a range of hormones, including adrenaline, noradrenaline and cortisol.

Unlike most physical dangers, which thankfully tend to be short-lived for most of us, emotional dangers or “stressors” can sometimes be prolonged. In such situations our body’s danger response goes into over-drive and this can have some serious health implications. It is not uncommon for people suffering from chronic stress to have high blood pressure, chest pain, headaches and elevated blood sugar levels. These are all well-recognised physical symptoms that can occur as a result of elevated adrenaline and cortisol levels.

However, there are many other physical effects associated with stress that are less well-recognised. Some that have particular implications for many of my clients include the effects on the bladder, bowels and sexual function. When our threat response directs blood to our major muscles, there is a corresponding reduction in blood flow to other areas of the body considered less important in times of danger, including our digestive system, sex organs and immune system. This helps explain why many people under stress complain of an upset stomach, nausea, diarrhoea or constipation. Stress and danger can literally make you feel quite sick. In fact, stress can actually make you more likely to get sick too. The suppression of our immune system with stress means our bodies cannot fight off infection or heal as quickly, making you feel more run down, take longer to recover from injury and more prone to picking up infections. There is also a known link between stress and urinary frequency and urgency, making you need to urinate more often and have a harder time “holding on”. With all of this going on, it probably comes as no great surprise that emotional and physical stresses also tend to lower our sex drive, with reduced blood flow to this region playing a role as well.

What about the effect of stress or threat on pain? Is it “all in your head”? Well yes, but not in the way you think.

Pain is always created by the brain. The brain creates a pain response when actual tissue damage occurs, but can also do so when it considers there may be potential damage or threat. We are all familiar with the pain response we get when touching a hot surface, even if we haven’t actually burned ourselves. The brain will produce pain if it considers we are under threat – and this can include emotional as well as physical threats. As we saw before, the brain does not really see much difference.

Pain is one of the most complex and poorly-recognised symptoms that accompanies chronic stress. Cortisol is one of the hormones released under threat. Acutely elevated cortisol at the time of initial threat has an anti-inflammatory response. However, if the threat or stress is prolonged, cortisol levels become chronically elevated, and this has been found to promote inflammation. That’s right - chronic stress can increase inflammation. Add that to the increase in muscle tension that accompanies our “fight or flight” response, and we can see why many people under chronic stress will complain of muscle and joint pains, including neck and low back pain. If the tense, sore muscles happen to be in your pelvis, as happens with many pelvic pain disorders, this not only produces more pelvic pain (including pain with intercourse) but can also have further ill-effects on bladder and bowel function. So, stress or threat can contribute to pain and inflammation.

However, pain itself is also seen by the brain as a threat, especially when it has been prolonged. Prolonged or chronic pain often makes us start to worry why the pain is continuing. Surely there must be something terribly wrong? The less people understand about their pain and its causes, the more worried they can become. Some people with chronic pain may imagine all kinds of worst-case scenarios, which is sometimes called “catastrophising”. Catastrophising can become a vicious cycle where our worries or fears about the pain can become interpreted by the brain as a threat in itself, contributing to more cortisol release (and thus promoting more inflammation), more muscle tension, and thus more pain. Cortisol can also help to create fear-based memories, which can be especially powerful if the memory is associated with a significant past event, such as a major health scare or a powerful emotional trauma. The more often these fearful memories are reinforced, the stronger the physical response can become.

I saw a good example of this recently with a dear patient who had a past history of cancer. She had developed a sore hip after doing a lot more walking, but not surprisingly, her mind started to imagine “what if the cancer has come back”. The more she worried about it, the worse the pain seemed to get, and the greater the pain, the more she worried. When she came to see me, she reported, rather embarrassed, that she had seen her doctor only a few days before, who reassured her this was not a return of her cancer. “I feel silly – the pain has been so much better since he told me that,” she said. I was not at all surprised and reassured her she was not at all silly. Her past memory of cancer had created a cycle of worry and fear about her pain, and these fears stimulated the threat response in her brain, contributing to greater pain (and a few poor night’s sleep to boot!). Therefore, we can see that stress and threat can contribute to pain, but pain can also feedback to create more stress, worry and fear, making the pain worse.

My patient’s story gives us some insight into how we might tackle our body’s automatic “fight or flight” response, so our stress, worry or grief are not forever making us sick or causing ongoing pain. One way is to use our higher-level brain function to dampen down our innate response. The pre-frontal cortex, the area of the brain responsible for higher level thought, can over-ride our automatic response. Using logical thinking to work our way through worries, having a good understanding of why we might be experiencing pain (and that it’s not something terrible) or thinking of happy memories of the person we grieve for, are all good examples of how we can use our pre-frontal cortex to quieten our threat response. This is why it is important for many people with chronic pain to have thorough education on the mechanisms, including non-physical factors, which can contribute to their pain.

Another way we can dampen down our threat response is by trying to engage the parasympathetic nervous system – sometimes referred to as the “rest and digest” part of our automatic brain response. Doing activities which encourage relaxation and enjoyment can all help to promote more parasympathetic activity. This can include activities such as mindfulness, deep breathing, doing regular exercise and making time to do things you enjoy. These activities are good for all of us, but especially important for people under-going stress, worry and grief.

The take home messages here are, the brain does not distinguish between physical and emotional threats. It treats both in a similar way and responds with its automatic “fight or flight” response in both cases. This sympathetic nervous system response has far-reaching effects on our bodies and can, quite literally, make us sick and cause pain. However, we can actively do things to help dampen this response and take back control. After all, life is always going to have its ups and downs, but how we respond to these can make or break us.


If you have any questions about any of the information in this blog, please contact me at Life Cycle Physiotherapy.

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