We all experience stress from time to time. It's part of the human condition. Despite its frequency, however, the term "stress" is often misunderstood. Let's define it. According to the dictionary, stress is "a physical, chemical or emotional factor to which an individual fails to make a satisfactory adaptation and which causes physiologic tensions that may be a contributory cause of disease.

Let's examine this definition more closely. First, note that stress can be physical, chemical or emotional. This also means that it can be either external or internal. An emotional stress can, for example, be produced by an external event that is witnessed or experienced, or by an internal dream or memory. Physical stress can come from an injury or excessive exercise, among others sources. Chemical stress can come from a medication, recreational drug or toxin. All of these stressors produce a reaction in one's mind and body.

And it's the reaction that's crucial. The definition states that stress occurs when "an individual fails to make a satisfactory adaptation" to the stressor. If one adapts to the stressful factor, then one can say that stress has not really occurred. Such stressors are often termed "good stress" because they tax the mind and body without injuring it. We all know people who seem to thrive on certain types of stress. Exercise is a good example of external stress that produces no detrimental effects on most people; on the contrary, this type of stress produces benefits rather than harm.

Here we confine ourselves to stressors to which one does not adequately adapt and thus create detrimental responses. Remember that each of us responds to stress in his or her unique way. Typically, even though the source of stress may change, one's particular pattern of responses remains the same. In other words, a wide variety of different stressors tend to create a very small range of responses in a particular person.

For example, some of us usually feel stress in our bodies, developing neck pain or headaches. Others sense it in the mind or emotions, becoming sad, anxious or ill tempered. Many of us show stress in our behavior, eating or drinking more when stressed, or heading for the mall to shop. And occasionally, only those around us know that we're stressed, and they tell us so. Whatever the response, it represents a "physiologic tension" that gradually (or not so gradually) takes its toll.

Some responses to stress are less adaptive than others. And many can be detrimental to physical and/or mental health. Over time, stress "may be a contributory cause of disease," as the definition states. The list of diseases to which stress contributes is quite long, ranging from the common cold to heart disease to depression. So in addition to its unpleasant immediate effects, stress also has detrimental long-term harms. It thus makes sense to learn how you respond to stress so that you can begin to substitute maladaptive responses with beneficial ones.

In the Stress Style Profile, we look at the specific ways in which you respond to stress, and how they may be affecting your health. In the Recommendations, we give some suggestions on how to deal with stress in more adaptive ways, so that you can minimize its effect on your health.