Its psychological uses are frequently metaphorical rather than literal, used as a catch-all for perceived difficulties in life. It also became a euphemism, a way of referring to problems and eliciting sympathy without being explicitly confessional, just "stressed out". It covers a king-size extension Stress Balls of phenomena from mild irritation to the amicable of severe problems that might result in a certain breakdown of health. In hip usage almost any business or situation between these extremes could be described as stressful. The most extreme events and reactions may elicit the diagnosis of Posttraumatic stress disorder.

The head stress was first fanatic by the endocrinologist Hans Selye in the 1930s to identify physiological responses in laboratory animals. He later broadened and popularized the hypothesis to include the perceptions and responses of humans trying to adapt to the challenges of everyday life. Stress, in Selye's terminology, refers to the reaction of the organism, and stressor to the perceived threat.