The terms "eustress" and "distress" are widely used throughout the scientific literature. As of February 2020, 203 items in the Web of Science show up in a search for "eustress," however, there are almost 16 400 items found in a search for the term "distress." Based on the reasoning in this article, however, it is believed there is no such thing as eustress or distress. The adaptation reaction of an organism under stress is not intrinsically good or bad, and its effect on health or performance depends on a plethora of other interactions of the body with the environment as well as on the history of such interactions. The vagueness of the terms "eustress/distress" has historically led to vast differences in the perception and application of the terms across disciplines. While psychology or sociology perceive eustress as something inextricably linked to positive perception and enhanced cognition, biomedicine perceives eustress as generally associated with better survival, health, or increased longevity, no matter how the event is perceived. In this paper, the authors review the current understanding of the term "eustress" in different fields, discuss possible implications of its misleading use, and suggest that the term may be replaced by "stress" only.