A little stress boosts immunity – but chronic stress causes problems
By Paul Bolger. Chartered Physiotherapist at Nano Physiotherapy, Kilkenny (www.nanophysio.ie).
Last week we looked at what stress is – a key physiological response that allows living things to survive in this world. It is perfectly healthy and normal, but it can become a problem when it persists.
Why Does a Physiotherapist Care About Stress?
Why, as a physiotherapist, do I think that this is an important topic to write about?
One reason is the effect stress has on healing and recovery. Even for a straight-forward injury, like a sprained ankle or a small wound, excessive stress levels can negatively impact the healing process.
Another probably more significant reason is that for long-term problems, whether they be related to persistent pain or other health conditions, stress can play a key role in somebody’s risk of developing a problem, as well as in recovery and management of such problems.
Stress, The Immune System & Inflammation
One way stress impacts our health is by its effects on inflammation.
Acute stress increases immune activity – this can be seen as a preventative response to prepare us for potential injury. By firing up the immune system, a temporary increase in inflammation occurs.
It makes sense then that those suffering from auto-immune issues or inflammatory conditions may suffer from a ‘flare’ following periods of stress. Those suffering from persistent pain may also have a pain flare – with inflammation often making our whole pain system more sensitive.
Persistent Stress Reduces Immune Function
In the long run, frequent stress can suppress immune function. Part of a normal stress response includes the release of glucocorticoids from the adrenal glands (famous for releasing adrenaline), which sit on top of the kidneys.
The release of hormones called glucocorticoids, such as the hormone cortisol, is a normal part of the stress response. Glucocorticoids downregulate the release of other stress-related chemicals in the brain – in doing so they shut down the stress response.
With frequent and prolonged stress, increased levels of these hormones in the bloodstream act to dampen the stress response and, in doing so, suppress the immune system. In fact, those suffering from auto-immune problems (with over-active immune systems) are given glucocorticoids as medication to dampen their immune function and ease their symptoms.
More to Come
So, to sum up, stress is essential. Acute stress turns up our immune system, temporarily increasing inflammation. Sustained periods of stress cause problems – restricting immune function, leaving us at higher risk of infection and other health problems.
Next week we will continue to learn more about the interplay between stress and inflammation – with a focus on how this impacts pain.
