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 the autonomic nervous system. This is an essential part of the "fight or flight" response.
As well as triggering responses in muscles, such as 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 result in a heightened - or stressed - state that prepares your body for optimum performance in dealing with the situation.
The modern 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 health and reduce the ability to cope.
