The everyday meaning of stress is being under too much pressure, usually from work or other commitments. It can cause psychological and physical symptoms such as poor sleep, irritability and feeling anxious.

Some stress may help your body to prepare for certain challenges, so it’s probably impossible to live without any stress. But too much stress, especially if it’s day in, day out, can cause physical and emotional problems.

So that your body can respond almost instantly to challenges, many of its control mechanisms happen without you having to think about them. This involuntary control of things, such as how fast your heart beats, is achieved by a network of nerves called your autonomic nervous system. This is an essential part of the ‘fight or flight’ response.

As well as triggering responses in muscles, including your heart, your autonomic nervous system sends signals to your hormonal system, triggering the release of chemical messengers such as adrenaline. These are released into your bloodstream and travel all around your body contributing to the ‘fight or flight’ response by, for example, making you more alert, boosting your blood pressure and releasing sugars into your bloodstream. This results in a heightened – or stressed – state that prepares your body for optimum performance in dealing with a situation.

The stresses we face in our everyday lives – such as deadlines at work or money troubles – don’t really trigger a ‘fight or flight’ response. However, they do release the same stress hormones, and this natural reaction can damage your health and reduce your ability to cope. Overall, if you’re under long-term stress you’re at greater risk of developing disease or dying prematurely.

Symptoms of stress

Everyone reacts to stress differently. However, there are some common symptoms to look out for.

People who are chronically stressed may have:

• periods of irritability or anger
• apathy or depression
• constant anxiety
• irrational behaviour, mood swings and be over-sensitive
• loss of appetite
• comfort eating
• an inability to concentrate or make decisions
• loss of sex drive
• an increased likelihood of smoking, drinking, or taking recreational drugs

Effects of Stress

There can also be physical effects, which may include the following:

• excessive tiredness
• sleep problems
• tearfulness
• frequents colds and infections
• high blood pressure
• skin problems, such as eczema
• aches and pains from tense muscles, including neck ache, backache and tension headaches
• increased pain from arthritis and other conditions
• feeling sick and dizzy
• stomach problems including constipation, diarrhoea or ulcers
• for women, missed periods

Stress and illnesses

The exact role of stress in causing illnesses isn’t known. However, it’s clear that stress can temporarily weaken your immune system. If your body is put under too much stress, it can become exhausted.

Over time, the chemicals that are released during times of stress, and the changes they produce in your body can seriously damage your health. In the long-term, this may increase your risk of having a heart attack or stroke. Chronic (long-term) stress can also contribute to anxiety and depression.

You may also be more exposed to risk factors for diseases when you feel stressed. For example, smokers may smoke more if they’re stressed, and people who drink alcohol to relieve stress may become dependent on it.

Post-traumatic stress

Post-traumatic stress can affect anyone who has been through an extremely difficult or violent experience, such as witnessing a violent death or disaster, being involved in a serious car crash, or surviving a fire.

People suffering from post-traumatic stress may experience any of the symptoms listed. They may also feel a mixture of emotions such as fear, shame, depression, guilt or anger, and recurrent memories or images that may be haunting or lead to nightmares. These feelings can last for weeks, months or even years after the traumatic event that triggered them. Specialist treatment, possibly with medicines and psychological therapies, is available.