Stress is what our minds and bodies experience as we attempt to deal with the changing environment that affects our lives. We often think of pressure at work, queuing for services or rush hour traffic as stress. While these events may well be triggers, stress is actually the body's reaction to such factors and is activated by adrenaline and other stress hormones, which stimulate a variety of physiological changes. These changes include increased heart rate, blood pressure, faster breathing, muscle tension, dilated pupils, dry mouth and an increased blood sugar level. Stress is the increased stimulation that the body needs in order to defend itself when faced with danger.

Whenever we feel tired, anxious, tense and frightened, depressed or elated, we are undergoing stress. Stress is both acceptable and avoidable but it is a part of everyday life. Despite what the common and accepted view is stress is not a modern phenomenon; it has always been part of human existence and life without stress would be difficult to endure. Not all stress is undesirable. Physical and mental exercise, intense creativity and sex are the happy face of stress. It is only when real or perceived change overwhelms the body's ability to cope, that stress becomes harmful, leaving us prone to unwanted physical, emotional or mental reactions and illnesses.

The causes of stress are varied and multiplied but they can be divided into two general categories, which are external and internal. Examples of external stress include social interaction, the physical environment, daily problems and major life events. Internal stress includes lifestyle choices, stressful personality traits, mind traps and negative self-talk. These factors generate various symptoms of emotional and mental stress, the most common including anger, anxiety, worry, fear and depression.

Excessive, prolonged and emotional stress may have a harmful effect on mental, physical and spiritual health. If left alone, the feelings of anger, frustration, fear and depression generated by stress can set off a number of illnesses. Stress is without doubt the most common cause of ill health in today's society. Stress is a contributory factor in relatively minor conditions such as headache, digestive problems, skin complaints, insomnia and ulcers. It also plays an important role in the leading causes of death in the western world, which are cancer, suicide, cardiovascular disease, cirrhosis of the liver, respiratory disorders and accidental injuries.

Stress can also have a positive effect. Stress is very important for awareness and motivation. It provides the stimulation that we need in order to deal with demanding situations. Tension and arousal are necessary for the enjoyment of many aspects of life and without them existence would be extremely boring. Stress also provides the sense of alertness and urgency needed for survival when confronting threatening situations.

There is no single level of stress that is optimal for all people. We all differ in regard to how we perceive and react to events; what is distressing to one person will be the complete opposite to another. Even when we agree that a particular event is distressing, we are likely to differ in our physiological and psychological approaches to it. Some individuals are more sensitive to stress than others, owing to the experiences in childhood and the influence of teachers, parents and religion. It is important to remember that we self generate most of the stress that we experience. How we view life depends greatly on exactly how we regard ourselves. Self generated stress is something of a paradox because so many people think of external causes when they are depressed. Recognising that we create most of our own depression is an important first step towards coping with it.