What is Stress? Understanding Stress

See also: Tips to Reduce Stress

Stress, as most people understand the term, is a reaction to excess pressure. This may come from life events, work, or simply a feeling of being a bit out of control. The vast majority of people will suffer from stress at least once in their lives, and many live with it much of the time.

Unfortunately, too much stress can be very bad for your health, causing long-term problems such as high blood pressure and heart conditions. This page (part of a series of pages on stress management) provides an introduction to stress, and explains some of its most common causes and the symptoms that you may see as a result.

What is Stress?

Defining stress

The dictionary definition of stress includes hardship, strain, physical, emotional or mental pressure.

It is, therefore, a response to pressure, and particularly an inappropriately high level of pressure.

Stress can be described as the distress that is caused as a result of demands placed on physical or mental energy. Stress often affects behaviour, so that stress in one person is also likely to put stress on those around them, whether family, friends or colleagues.

Different people find different things stressful, and can also cope with different levels of pressure before becoming stressed.

For example, some people find it very stressful to be among large numbers of people and avoid crowds. Others like nothing better than the idea of a music festival, with thousands of people close together for a few days. Some people find too much work stressful, while many others would say that it is stressful not to have enough to do.

It is therefore important to remember that stress is personal, and not judge others by your standards of stressfulness.

Causes of Stress

Stress can arise as the result of a number of factors, including life events, work, and behaviour of others.

These will vary for different people, although there are likely to be some that we would all agree are stressful, such as losing your job, separating from your partner, and moving to a new house.

Stressful life events

Many of the most stressful situations in life come as a result of unplanned changes in personal circumstance. There is some evidence, in fact, that what is actually stressful is not so much the event itself, as the feeling of being out of control of your own life.

The following list is compiled from the answers given by a large number of people as to how hard it is to readjust to different life changing events.  A high score shows that people find it hard to readjust to that event, which in turn indicates a high stress factor.

Event: Score out of 100
Death of a Spouse or Partner 100
Divorce 73
Marital Separation 65
Death of a Close Family Member 63
Personal Injury or Illness 53
Marriage 50
Loss of a Job 47
Marital Reconciliation 45
Retirement 45
Change in Health of a Family Member 44
Pregnancy 40
Sexual Problems 39
Addition of a New Family Member 39
Death of a Close Friend 37
Change to a Different Kind of Work 36
Taking on a Large Mortgage 31
Change of Responsibilities at Work 29
Son or Daughter Leaving Home 29
Spouse Starts or Stops Work 26
Starting or Leaving School 26
Trouble with the Boss 23
Change in Residence 20
Taking on a Loan 17
Change in Eating Habits 15
Holiday 13
Christmas 12
Minor Violations of the Law 11

Based on: Holmes and Rahe's Life Change Index; Journal of Psychosomatic Research, 1967, Vol. 11, pp. 213-218.

Life changes can have a direct effect on health, either good or bad. People who have high-stress life changes often become ill afterwards. Most people consider that the death of a spouse is the most stressful change in life. Widowers are 40% more likely to die than other people, and also have high rates of illness and depression.

It is not only unpleasant events that can be stressful. Almost any change in circumstances can cause stress as we readjust. If possible, it is wise to not have too many changes in life at the same time.

Certain situations can also lead to people feeling stressed, although the degree of stress will depend, amongst other things, on that individual’s coping strategies.

For example, environmental factors can make us stressed. Aspects like the level of noise, crowds, poor lighting, pollution or other external factors over which we have no control can cause us to feel anxious and irritable.

Adjusting to modern-day life can also be a source of stress. We now communicate with people in many different ways, e.g. through the Internet, mobile phones, and various broadcast media, and the expectation of a quick response has increased. In one survey, 12% of respondents said that feeling that they had to respond instantly to messages was stressful. Social media has also been linked to stress and other more serious mental health problems, partly because it enables comparison between your (unedited) life and others’ (carefully curated) experiences. This is particularly likely to be a problem for younger people, especially teenagers.

There is more about this in our page on Social Media and Mental Health.

We also have many more commodities available to us and some people feel an expectation to maintain a certain lifestyle and level of consumerism.  In addition, many people are now both working and caring for children and/or older parents. All these changes mean that stress is now unfortunately commonplace in both our personal and professional lives.
More importantly, perhaps, stressors do not have to be ‘big ticket’ items. Ongoing small aggravations and issues, especially if left unmanaged or unchecked over a long period, can often become stressful. It can also be hard to recognise these as problems because they seem so small—but over time they mount up.

There is more about these issues, and how to recognise and manage them, in our page on Understanding Micro-Stressors.

Stress at work

One particular environment where many people experience stress is at work.

Stress at work may be the result of being asked or expected to do too much, or work very long hours. It can also, however, be the result of not being given enough work, or not having a clear enough understanding of what is expected.

As with any form of stress, the root problem is often the feeling of not being in control.

There is more about stress at work in our page on Workplace Stress.

Signs and Symptoms of Stress

There are a number of common signs and symptoms of stress, and stress can also lead to more serious problems and illnesses.


Anxiety is caused when life events are felt to be threatening to individual physical, social or mental well-being. The amount of anxiety experienced by an individual depends on:

  • How threatening these life events are perceived to be;
  • Individual coping strategies; and
  • How many stressful events occur in a short period of time.

Anxiety is quite normal, and most people become anxious from time to time. However, anxiety can become a problem if it affects your ability to manage your life, or deal with the things that are causing your anxiety. In one survey, 61% of people feeling stressed also reported feeling anxious.

See our page: What is Anxiety? for more information.


Tension is a natural reaction to anxiety or stress. It is part of a primitive survival instinct where physiological changes prepare the individual for ‘fight or flight’ through the release of the hormone adrenaline.

This sympathetic response, as it is known, results in a chemical called adenosine triphosphate (ATP) being released into the body and causes muscles to tense ready for action. As a result of the adrenaline, the blood vessels near the skin constrict to slow bleeding if injury is sustained and to increase the blood supply to the muscles, heart, lungs and brain. Digestion is inhibited, the bladder relaxes, the heart rate and breathing speed increase, and the body sweats more. You become more alert, your eyes dilate, and you get a surge of energy.

These responses are extremely useful in situations of physical danger: when you are being chased by a wild animal, for example.

However, for most of us nowadays, anxieties cannot be solved by a ‘fight or flight’ reaction or by any physical response.

Modern stressful situations tend to continue for much longer periods of time. An immediate response does not usually relieve the anxiety-provoking situation. We therefore end up living in a prolonged state of anxiety, which can lead to the symptoms commonly associated with stress. These prevent individuals from relaxing and can therefore be detrimental to health and wellbeing.

Physical Signs of Stress

In addition to feeling uneasy, tense and worried, physical sensations of continued stress can include:

  • Palpitations or chest pain
  • Dizziness
  • Indigestion or heartburn
  • Tension headaches
  • Aching muscles
  • Trembling or eye twitches
  • Diarrhoea
  • Frequent urination
  • Insomnia
  • Tiredness
  • Impotence
  • Rashes that look a bit like an allergic reaction

Continued stress can lead to feelings of lethargy and tiredness, migraine, severe stomach upset and sleeplessness. Severe stress can also lead to panic attacks, depression, chest pains, phobias and fears of being seriously ill.

As with all such symptoms, you should seek the help and advice of a healthcare professional.

Stressed people may also have higher blood pressure, which can be damaging in the long-term. Similarly, high levels of stress can suppress your immune system, making you more likely to become ill.

A key issue is to recognise that these symptoms are caused by stress. Once this is clear, you can start to take action to manage the causes, and not just the symptoms, for example, by using stress reduction techniques.

See our page on Avoiding Stress for more information about how to avoid and reduce stress in your life, including through relaxation techniques.

Long-Term Effects of Stress

As well as these immediate and short-term signs and symptoms, stress can also have long-term effects on both your body and mind.

For example, several research studies have found long-lasting effects of particular stressors or general stress, such as:

  • One study in the US found that low-income students of colour who were considered ‘psychologically successful’—that is, they had a good sense of self-control and persistence—aged faster at a cellular level. This is a predictor of chronic health problems in later life, and even earlier death.

  • A meta-analysis of 187 studies found that stressful experiences in early life were linked to markers of inflammation in the body. This effect seemed to last well into adulthood.

It should therefore not be surprising to find that chronic stress is often associated with long-term health issues, many of which are an extension of the immediate symptoms. These include:

  • Digestive problems such as weight gain or loss, irritable bowel syndrome and ulcers;

  • Mental health problems such as depression or anxiety, which were reported by more than half of people feeling stressed in one survey in the UK;

  • Immune system problems such as fibromyalgia and psoriasis; and

  • Heart problems, such as high blood pressure, increased heart rate, and palpitations.

Some people also turn to problem behaviours to manage their stress. These might include drinking alcohol, over- or under-eating, gambling, smoking, or misusing substances. One survey in the UK found that nearly half of those surveyed (46%) said that they ate too much or ate unhealthily because of stress. A total of 29% reported that they started drinking or increased their level of drinking, and 16% reported that they started smoking or increased their level of smoking, to cope with stress. These behaviours can become addictions, which in turn are likely to cause further problems.

These problems may last for many years, often manifesting long after the initial stress has passed or been removed. It is therefore important to take steps to avoid and manage stress as early as possible.

Preventing and relieving stress

The first step to being able to reduce stress is recognising it. You can only do this if you understand what triggers your stress, and your personal signs of stress. For many people, a personal programme of stress management, focused on stress prevention as much as stress management and reduction, is now an essential part of modern living.

The Skills You Need Guide to Stress and Stress Management

Further Reading from Skills You Need

The SkillsYouNeed Guide to Stress and Stress Management

Understand and Manage Stress in Your Life

Learn more about the nature of stress and how you can effectively cope with stress at work, at home and in life generally. The Skills You Need Guide to Stress and Stress Management eBook covers all you need to know to help you through those stressful times and become more resilient.