There is no medical definition for stress, but this is one that clearly defines stress:

“Stress is a threat to the quality of life and to physical and psychological well-being”
(Tom Cox)

Stress is affecting most of us because of the speed of life, and stress is in fact a symptom which is caused by too much pressure. Stress means that we get to a certain point when we are unable to cope with pressure; this is often the case with carers, who experience so many demands in caring, as well as those of everyday life. Incidents of stress are increasing and it affects most people, with a high percentage of illnesses being attributed to stress. It can compromise the immune system, leading to more colds and infections, and over a long period of time can cause various aches and pains. In particular these may be musculo-skeletal: painful shoulders, or a sore neck or back.
There is growing evidence that stress is an important factor in the development of some diseases and conditions such as high blood pressure, asthma, migraine, diabetes, ulcers, insomnia, and coronary heart disease. It is important to be aware of the signs and symptoms so that you can take action before illness develops from long-term periods of stress.

A reaction to stress can be either a physical or a psychological response to a stressor, and could be headaches, inability to sleep, anxiety, and depression. Prolonged exposure to stress is linked to anxiety and depression, as well as to physical conditions such as heart disease, back pain and headaches.
As a carer, it is important to look after yourself and in particular your emotional and physical health. A build-up of pressure can result in feeling stressed and unable to cope. There are times when you will not know what is causing the problem, but you will see as you read through this book that stress affects virtually every system in our bodies.
Work-related stress accounts for over a third of all new incidences of ill health. This can be due to many different causes which you will find later in the book.

It is sometimes referred to as the ‘silent killer,’ as it tends to be insidious to begin with and is a state of tension which is created when a person responds to the demands and pressures that come from work, family and other external sources, as well as those that are internally generated from self-imposed demands, obligations and criticism. Stress can be cumulative and can add up over a period of time until a state of crisis is reached and symptoms appear. These symptoms may manifest themselves psychologically as irritability, anxiety, impaired concentration, mental confusion, poor judgment, frustration and anger. They may appear physically as muscle tension, headaches, low back pain, insomnia and high blood pressure.