What stress is: what your body switches on, when it stays on, and what a stress scan measures

What stress is exactly

In this article you read the answer to the question what is stress: what your body switches on under tension, when short tension becomes long tension, which signals your GP works with, what long tension does to the heart and to the rest of your body, and what a stress scan can and cannot measure. That matters, because one word covers two different things, a switch that helps you through a hard hour and a load that builds up over months, and only that load eventually brings people to the GP. The BioProfile stress scan measures how much tension you are carrying now and gives you an indication of where you stand today in this area, as one of the 11 health areas that the full scan assesses. This is not a diagnosis. It is insight, to see where you stand today, and to help you make better choices in your food and lifestyle. What this scan does not do: point to a cause. What is going on is for a doctor to name.

The research word for that switch is allostasis: the body reaches stability by turning the stress systems on. The word for the bill is allostatic load, or overload, the wear on body and brain when those same mediators stay on too long.⁠² In plain words: the response itself is normal and useful. The problem starts where the off switch is never used.

Dutch patient information says the same thing without the biology. Thuisarts.nl (NHG) defines the state that stress causes in one sentence: ‘You become overstrained when you have a lot of tension in your life and you cannot cope with it well.’⁠¹

The signals your GP works with

Thuisarts.nl draws the line at 3 or more complaints from one list: feeling tired, sleeping badly, getting irritated quickly, not being able to handle noise or crowds, crying often, worrying a lot, feeling rushed, finding it hard to concentrate and remember, plus physical complaints such as headache, dizziness, chest pain, palpitations and stomach complaints. On top of that comes the feeling that you have lost your grip and can no longer manage your daily tasks: work, the household, contact with others.⁠¹ That combination, and not one bad week, is what Dutch primary care calls overstrain.

Long tension also feeds itself through behaviour. Chronic stress goes together with sleeping less, eating worse, moving less and using more alcohol, tobacco or other substances.⁠² Each of those adds to the same load, and that is why the list of signals and the list of habits usually grow together.

What is healthy stress and what is chronic stress

Short tension is not the enemy. In 21,501 adults aged 18 to 70 in the Netherlands, occasional work stress even went together with slightly less type 2 diabetes (adjusted prevalence ratio 0.82; 95% CI 0.75 to 0.93).⁠⁶ Regular stress at home went the other way in the same group (1.15; 1.03 to 1.28), and major life events in the 12 months before went together with 1.22 (1.03 to 1.41) in the group as a whole and with 1.48 (1.21 to 1.76) in the group of Dutch origin.⁠⁶ Read simply: a demand that passes looks different from a demand that never goes away.

Chronic stress is the kind with a clock on it. Thuisarts.nl marks burnout with a duration: ‘You have been tired and exhausted from the tension in your life for longer than 6 months.’⁠⁷ What that long load does has been checked across 267 original studies: allostatic load and allostatic overload go together with poorer physical and mental outcomes, in samples from the general population just as much as in clinical ones.⁠³ In the brain, chronic stress makes the dendrites in the hippocampus and the medial prefrontal cortex shrink, while the dendrites in the amygdala grow larger, changes that go together with more anxiety and with weaker thinking and remembering.⁠² That is the honest version of a head full of cotton wool: it has a shape in the tissue.

The Dutch figures show how ordinary this is. In 2025, 20.7 per cent of employees aged 15 to 74 had burnout complaints, 18.0 per cent of men and 23.5 per cent of women, with a peak of 28.2 per cent at 25 to 34 years and a low of 8.5 per cent at 65 to 74; among self-employed people the figure was 11.8 per cent.⁠⁴ Sick leave follows: 8.8 per cent of the most recent absence among employees who were ill at least once in the past 12 months was caused in 2025 by mental health complaints, overstrain or burnout, against 5.7 per cent in 2014.⁠⁵

What is a stress heart: what long-lasting tension does to your heart

The largest measurement of tension at work and the heart pooled 197,473 employees without coronary heart disease from 13 European cohorts, including the Netherlands; 30,214 of them, 15 per cent, reported job strain. Across 1.49 million person-years, on average 7.5 years, there were 2,358 new events of coronary heart disease, and the hazard ratio for job strain was 1.23 (95% CI 1.10 to 1.37). The population attributable risk was 3.4 per cent.⁠⁸ In plain words: a modest step up in risk for the individual, and a small slice of all heart disease at the level of a country.

Part of that runs through the rest of your life. In 47,045 men and women, work pressure went together with diabetes (odds ratio 1.29; 1.11 to 1.51), physical inactivity (1.34; 1.26 to 1.41), smoking (1.14; 1.08 to 1.20), obesity (1.12; 1.04 to 1.20) and a Framingham Risk Score of 20 per cent or more (1.13; 1.03 to 1.25), while blood pressure and blood lipids showed no association.⁠⁹ So the heart story is less about the blood pressure cuff on a tense day and more about the habits a tense year builds up.

The heartbeat itself also carries a signal. A meta-analysis and review of 37 studies found that heart rate variability changes under stress, most often as low parasympathetic activity: the high frequency band goes down and the low frequency band goes up. The authors conclude that heart rate variability has enough neurobiological grounding to serve as an objective measure of mental health and stress, and that this measure is linked to the appraisal of threat in the ventromedial prefrontal cortex.⁠¹⁰

What a stress scan measures, and what the scan does not measure

The same review of 267 studies that described the load also said how to weigh it: assess the accumulated stress load with an integrated approach, biological markers together with clinimetric criteria.⁠³ A questionnaire is one half of that. The stress scan asks about the past two weeks and converts your answers into a score, with the range the score falls in, so you have a number instead of an impression your memory flattens.

What questions cannot do is name the cause of the tension. Money, a job, a loss, poor sleep and a low mood all read the same in a list of answers. The scan is a picture of your load and a starting value. It is not a diagnosis, and only a doctor can tell you what is going on.

What you do with tension that stays

The load drops when the systems that switched on are allowed to switch off again, because staying on is what does the wear.⁠² Thuisarts.nl names the first step simply: ‘Talk about it, including with your GP or practice nurse.’⁠⁷

Go to your GP if you think you are overstrained. Your GP goes through it with you in one or more consultations, sometimes with questionnaires, and may ask your partner or a family member to come along. If the symptoms last longer than 6 months and the exhaustion is the main feature, that points to burnout rather than overstrain.⁠¹

In summary

Stress is your body switching on its systems to meet a demand, and the load is what stays behind when those systems never switch off.⁠² Dutch primary care recognises the state as overstrain when you have 3 or more complaints from one list plus the feeling that you are losing your grip, and marks burn-out beyond 6 months of exhaustion.⁠^1,7 Short-lived tension can pass without a trace, while long-lasting tension shows up in your heart figures, in the habits around it and in the national figures.⁠^8,9,4 A stress scan gives you one number for how much of it you are carrying today, and a starting value to repeat. It is not a diagnosis.