Stress is not necessarily a bad thing. We all get stressed out once in a while.
In fact, stress is the warning system of the body. When the brain perceives danger, it floods the body with stress hormones and prepares us to respond to the potential threat. In small doses, stress even has many advantages; it helps us meet daily challenges, and motivates us to reach our goals.
Good stress is called 'eustress' and is considered healthy. It is only when stress (rather 'distress') is prolonged, not managed, and becomes chronic that it begins to have harmful effects on the body and mind.