Stress and Health

What is stress? Can too much stress make us ill? Might some stress actually keep us healthy?

What is stress?

Stress is a feeling of being under too much emotional or physical pressure. This pressure becomes stress when we feel we can't cope. Each of us perceives and deals with stress differently. That’s why sometimes the same potential stressor can have opposite effects for two individuals. For example, one person may perceive taking on a new responsibility at work as stressful whereas another may see it as a stimulating challenge.

Symptoms of Stress

Our body, perception, mental state and behaviours are all affected by stress. Common physiological signs of stress are irregular sleep, sweating, loss of appetite and difficulty concentrating. Mental disruption caused by stress can include racing thoughts, anxiety, loss of temper easily and substance misuse.

Can too much stress make us ill?

Stress and Illness by Tracey B Herbert and Sheldon Cohen, explained how stress can lead to illness:

If we’re under stress, our heart may react by beating erratically or very quickly. This may lead to cardiac problems or cardiac arrests. Moreover, if the body is under constant stress the hormones produced may increase the likelihood of our artery walls narrowing. This can decrease the levels of oxygen that reach the heart and ultimately cause angina or heart attacks.

White blood cells are an important part of the immune system which defend us against illnesses. Being in a low and depressed mood decreases the functions of the white blood cells. The low levels of white blood cells will in turn increase the likelihood of the body catching infections, and if infected already, take longer to recover.

A 2008 review of the evidence confirmed a link between chronic stress and both mental and physical illness. For example it suggested that chronic stress also increases the risk of diabetes, asthma attacks and stomach ulcers.

A study of more than 10,000 civil servants, reported in the BMJ in 2011, reported that those who experienced chronic work stress were at significantly greater risk of metabolic syndrome (a cluster of risk factors that increase the risk of heart disease and type 2 diabetes).   

Possible indirect health effects

Stress may also lead to a change in health practices and changes in following medical advice. For example, when the spouse of an elderly person dies, routines and habits are often disrupted. These disruptions may cause changes in healthy eating habits, or an increase in drinking which may lead to non restful sleep. This is particularly problematic should the individual have pre-existing health problems.

This fits with information from the Mayo Clinic, which suggests stress may have both a direct health effect (on blood pressure) and an indirect health effect (where it leads to smoking or overeating due to nervous tension). 

A 2011 meta-analysis, updated in 2013 showed that stress, anger, and depressed mood can act as acute triggers of major cardiac events – with a 2.5 fold increased risk of acute coronary syndrome onset being preceded by stress; and a 1.3 fold increased risk of coronary heart disease arising from workplace stress. 

A 2009 systematic review – suggested it is chronic stress (ie continuing long term) rather than acute (eg serious one off) which may be associated with hypertension. 

But no link between stress and cancer? 

On a more positive note, no link between work related stress and cancer or stress and cancer seems to have been proven so far – according to a 2013 meta analysis of studies involving 116,000 European men and women and also the US National Cancer Institute 

Are some of us more genetically predisposed to stress?

Some initial research has suggested that our genes may influence how easily we become stressed - and also how well we cope with stress. However, more research is needed to be clear about this. 

Might some stress actually keep us healthy?

That’s what the theory of hormesis suggests ie repeated but not continuous mild stress helps keep the immune system resilient. So far this theory relies on evidence from trials in creatures like rats rather than humans, so may or not be applicable in practice.

However, in evolutionary terms this would probably make sense. For most of our time on earth humans have been susceptible to stress (hunting or being hunted, experiencing famine and drought, working very long hours with few holidays, vulnerable to wars and crimes). If we fell ill quickly as a result then the human race probably wouldn't have survived. We're actually quite a resilient and adaptable species.


  • Stress is a feeling of being under too much emotional or physical pressure.
  • Repeated but not continuous mild stress is probably good for us – helping build our resilience.
  • However, chronic stress (i.e. significant and prolonged) can increase the likelihood of both mental and physical illness ( including angina, heart attack, type 2 diabetes and catching infection), as well as adopting unhealthy habits, such as drinking too much.
  • There’s no evidence so far that stress causes cancer.

Regine Wong, September 2013, Reviewed and updated by Emma Juhasz, December 2016 , Next review date, September 2019

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Stress Management Society