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The Centre for Studies on Human Stress (CSHS) is dedicated to improving the physical and mental health of Canadians by empowering individuals with scientifically grounded information on the effects of stress on the brain and body.
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Two broad categories of stressors

A stressor is anything that causes the release of stress hormones. There are two broad categories of stressors: Physiological (or physical) stressors and Psychological Stressors.

Physiological (or physical) stressors

These are stressors that put strain on our body?(i.e.: very cold/hot temperatures, injury, chronic illness, or pain).

Psychological Stressors

These are events, situations, individuals, comments, or anything we interpret as negative or threatening (i.e.: not being able to find a babysitter for your sick child when you cannot take time off work).

An easy way to remember the difference between the two categories of stressor is that absolutely everyone exposed to an absolute stressor will find it stressful. For a relative stressor, situations are relatively stressful only for some.


Scientists are now proposing that stressors can be further divided into:

Absolute Stressors

These are stressors that everyone exposed to them would interpret as being stressful. These are objective stressors that are universal (i.e.: earth quakes, a tsunami, or the events of September 11th 2001).

Relative Stressors

These are stressors that only some exposed to them would interpret as being stressful. These are subjective stressors that cause different reactions in different people (i.e.: time pressure at work, traffic, paying taxes, writing an exam).

Take home message
Stressors, whether absolute or relative, cause the release of stress hormones.

These days, absolute stressors are few and far between. Stress is highly personal because we have to interpret a situation as stressful. Although what stresses you is surely different from what stresses others.

However, there are common elements to situations that stress everyone. In fact, there is a universal recipe for stress!