What Causes Stress? Internal and External Stressors.

Stressed person

Stress is a normal part of life. In fact, psychologist Richard S. Lazarus proposed the idea that all humans need a manageable amount of stress in their lives in order to develop a healthy psyche.

But when our stress response becomes prolonged, or constantly triggered, things start to become problematic... In this article, we will take a look at what causes stress and why we get it:

What is stress?

Stress is a natural human response to situations or factors which are perceived to be threatening or difficult to manage.

Stress can be caused by internal or external ‘stressors’:

  • Internal stressors include our feelings and expectations.
  • External stressors arise from the environment and events taking place around us.

A healthy stress response develops quickly when required, in proportion to the provocation, and then fades away when no longer required. When stress is triggered in this way, it can actually be helpful for our survival, and serves to enhance motivation and productivity.

What is stress for?

Today, when we talk about stress it is rarely positive. Yet it is important to understand the vital role that stress has played in our evolution.

The “fight or flight” response, also known as the “stress response” is your body's natural response to a situation where you perceive that you are in danger; your brain signals to your adrenal glands to release hormones including adrenaline (epinephrine) and noradrenaline (norepinephrine) to produce a heightened state. This state is then predominantly maintained by the release of the hormone cortisol.

A heightened state is designed to result in:

  • Increased energy levels (via increased blood sugar)
  • Heightened alertness
  • Faster breathing and respiration
  • Reduced digestive function (sometimes leading to a reduced desire to eat)
  • Dilated blood vessels
  • Faster heart rate and higher blood pressure
  • Greater blood supply to the muscles

It is easy to see how this stress response may be extremely useful if you were faced with a sabretooth tiger, for instance. Not so helpful, however, to assist you with many of the not so life threatening challenges that we face today.

What types of stress are there?

1) Acute stress
Acute stress is the most common. It is usually related to events which have occurred in the recent past, or which you anticipate will happen in the near future. Examples of acute stress may include being involved in a recent altercation, or a deadline at work you are expecting.
An isolated episode of acute stress may lead to muscle tension, headaches or an upset stomach. But if you regularly experience acute stress, things can quickly become much more serious...

2) Episodic acute stress
If you regularly experience episodes of acute stress, this is known as episodic acute stress.
The causes of episodic acute stress may be internal or external stressors:
For example, you may have a job or life which regularly throws threatening or stressful situations at you (external). Or you may perceive yourself as having insufficient time or energy to handle recent or upcoming events (internal).
For some of us experiencing this type of stress, it can become a serious threat to our health in the form of high blood pressure or heart disease.

3) Chronic stress
Chronic stress occurs when we experience long-term, ongoing stress. This is usually the kind of stress we feel we cannot escape from. It may be caused by an early-life traumatic event. Or it may arise later in life, following an event we perceive to be life-threatening. This kind of stress includes PTSD (Post Traumatic Stress Disorder) as experienced by soldiers and other survivors of combat, disasters, serious accidents or physical and emotional abuse.
Chronic stress is so powerful that it can permanently alter our personality, leading to heart attacks, strokes, and even episodes of violence and suicide attempts.

Stressed person

What are the causes of stress?

The causes of anxiety, pain and suffering associated with stress can be placed into two categories:

1) External causes of stress External causes of stress are relatively easy for us to understand. This is because most of us find ourselves facing this kind of situation every day.
External stressors can include:

  • Relationship problems
  • Moving house
  • Commuting or sitting in traffic
  • Serious injury or chronic illness
  • Dramatic changes in your life
  • Marriage or divorce
  • Financial stresses
  • Family bereavement
  • A huge number of situations relating to work

The last stressor on this list; work stress, is such a significant contributor to our overall levels of stress that it deserves further exploration.

What causes stress at work?

Work is one of the most common causes of our stress. It occupies such a significant proportion of our time that stress can arise from a number of different situations, including work that:

  • Is dangerous
  • Is in a high-pressure environment
  • Involves long hours, lots of deadlines or a heavy workload
  • Is lacking in a sense of control in the work decision making process
  • Places unclear expectations on us
  • Places increasing, especially unfair, demands on our time
  • Is irregular or insecure
  • Includes bullying or harassment in the workplace
  • Has just been lost

2) Internal causes of stress
External stressors are caused by situations that arise outside of us, and outside of our control. You can't prevent your boss from firing you, or demanding that you come in for extra hours at the weekend.
Internal stressors, however, come from within you. These stressors might be related to:

  • Your perception of events
  • Your expectations
  • Your standards
  • Your desires
  • Measuring yourself against situations or others
  • Your personal goals

Further to this, internal stressors within you can exacerbate any external stressors that arise. For example, if we are already struggling with high personal expectations and standards which we are not always able to meet, we may have our stress levels sent through the roof by a late-running train, or unexpected traffic jam.
If we are not suffering from internal stressors, the resulting stress from these situations may be quite manageable.

Stress relief with Yoga

Dealing with stress

When it comes to dealing with stress, it is best to focus on the things that we can control. This means targeting our internal stressors, in order to reduce the impact they can have on any external stressors that are occurring in our lives.

Reducing the way we cope with internal stressors is not an easy process but here are some stress relieving strategies that can help:

1. Concentrate on solutions rather than problems: Focussing on how insurmountable a problem is will almost always make you feel worse. Instead, concentrate on solutions to the problem rather than the challenges themselves.

2. Keep a positive state of mind: The more negative you are, the more negative everything seems to be. How we perceive the world around us dictates how we feel and studies have shown demonstrated the power of positive thinking upon stressful situations.

3. Look into stress-relief: There are a number of stress relieving products available today, from pocket therapists and relaxing soundtracks to more advanced technology including neurofeedback and brain entrainment devices.

4. Consider meditation, yoga or tai chi: There are many different approaches that can teach you appropriate relaxation and body awareness skills. With practice, these disciplines can help you bring your stress levels under control.

No matter the cause of your stress, making the decision to act is the first step on your way to living a happier life. Whatever you do, don't just sit there and suffer in silence.


Samuel Maddock is a registered osteopath and health technology researcher. He has over a decade’s experience researching the latest innovations in health and wellness technology and consulting for health technology manufacturers to help improve product quality and effectiveness.

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