19 April 2013 Last updated at 17:43

What is stress?

Stress can cause headaches, high blood pressure and stomach upsets.

While we commonly think of stress as too much mental or emotional pressure, physiological or physical stress is also important. Stress can affect how you feel, think and behave as well as how your body works, because your mind and body constantly interact.

What is stress?

Stress causes a surge of hormones in your body. When your body detects stress, a small region in the base of the brain called the hypothalamus reacts by stimulating the body to produce hormones that include adrenaline and cortisol.

These hormones help you to deal with any threats or pressure you are facing - which is called the 'fight or flight' response.

Can exercise help?

Exercise helps to bump up the production of your brain's feel-good neurotransmitters, called endorphins
Regular exercise can boost self-confidence, mood and sleep quality, and lower the risk of depression
Exercise can reduce your risk of major illnesses, such as heart disease, stroke, diabetes and cancer
It can lower your risk of early death by up to 30%

Source: NHS Choices

Adrenaline increases your heart rate, raises your blood pressure and provides extra energy.

Cortisol, known as the stress hormone, also temporarily increases energy by triggering the release of glucose into the bloodstream, to help the person fight or run away. At the same time, other bodily functions which are not immediately needed, such as digestion, are suppressed.

The body's response to stress usually regulates itself. As your hormone levels fall, your heart and blood pressure will return to normal.

Everyone needs a certain amount of stress or pressure to live well. It's what gets you out of bed in the morning and motivates you throughout the day. However, stress becomes problematic when there's too much or too little.

Whilst a lack of stress means your body is under-stimulated, stress that is too intense or prolonged, causes your body to release stress hormones over a long period. This increases the risk of a range of physical health problems including headaches, stomach upsets and high blood pressure. It can even increase the risk of having a stroke or heart attack.

More often, stress leads to psychological problems. It can make people feel distrust, anger, anxiety and fear, which in turn can destroy relationships at home and at work. Stress also plays a key role in the development of anxiety disorders and depression.

Long-term stress can play havoc with your immune system, and a recent study suggests it raises the odds of developing viral infections.

Other research found people who suffered from chronic stress at work were at greater risk of developing metabolic syndrome, which is a combination of diabetes, high blood pressure and obesity.

Causes of stress

Many aspects of life can cause stress, such as money problems, work issues or difficult relationships. When a person is stressed, it can get in the way of managing responsibilities, which in turn can pile on yet more pressure. Having to cope with illness can compound these sorts of stresses.

The psychology of stress

The human brain has been described as the most complex object in the universe. And, because we all have unique experiences from which we develop our personalities, the complexity of human emotional life is immense.

The word "stress" is an unusual one. It is used to describe negative, difficult, emotions, or even mental ill-health. It's useful to think about three broad groups of causes of emotional difficulties - biological factors, social factors and life events.

Biological factors are very important. The structure and functioning of the brain - the nerves, synapses, and neurotransmitters - are vital to mental health. But human beings are much more than their biology...

People often feel over-stressed as a result of an event or 'trigger'. This doesn't have to be negative, such as the death of a loved one, redundancy or divorce, it can also be seemingly positive like a new partner, new job or going on holiday.

Feelings of stress can occur over a short period of time or can be chronic, for example when someone is coping with long-term unemployment or is stuck in a bad relationship.

People have different ways of dealing with stress. Some situations that may be motivating to one person, could feel stressful to someone else due to their personality type.

Recent research suggests our genes are closely linked to our personalities and may therefore dictate how susceptible we are to stress.

For symptoms, treatments and help managing this condition, please visit NHS Choices