The concept of "oxidative stress" in redox biology and medicine, introduced in 1985, has evolved significantly over the past three decades. This term encompasses the balance between aerobic metabolism and the potential strains that disrupt this balance, leading to biological stress responses. Research on molecular redox switches governing oxidative stress responses is thriving, with advancements in methodology enhancing our understanding of the link between redox shifts and signaling pathways. However, the term "oxidative stress" has been overused and misused, often without a clear relation to redox chemistry. The major role in antioxidant defense is played by antioxidant enzymes, not small molecule antioxidants. The field of oxidative stress research spans chemistry, biochemistry, cell biology, physiology, and medicine, with ongoing efforts to refine the concept and its applications. The term's appeal lies in its implicit notion of adaptation, reflecting the association of stress with stress response. Despite these merits, pitfalls include the overuse of the term in medical and public discourse, leading to a dilution of its meaning. Future research will focus on molecular redox switches, the role of redox in cellular energy balance, and the integration of oxidative stress with inflammation and disease processes.The concept of "oxidative stress" in redox biology and medicine, introduced in 1985, has evolved significantly over the past three decades. This term encompasses the balance between aerobic metabolism and the potential strains that disrupt this balance, leading to biological stress responses. Research on molecular redox switches governing oxidative stress responses is thriving, with advancements in methodology enhancing our understanding of the link between redox shifts and signaling pathways. However, the term "oxidative stress" has been overused and misused, often without a clear relation to redox chemistry. The major role in antioxidant defense is played by antioxidant enzymes, not small molecule antioxidants. The field of oxidative stress research spans chemistry, biochemistry, cell biology, physiology, and medicine, with ongoing efforts to refine the concept and its applications. The term's appeal lies in its implicit notion of adaptation, reflecting the association of stress with stress response. Despite these merits, pitfalls include the overuse of the term in medical and public discourse, leading to a dilution of its meaning. Future research will focus on molecular redox switches, the role of redox in cellular energy balance, and the integration of oxidative stress with inflammation and disease processes.