Stresses on healthcare systems and moral distress among clinicians are urgent, intertwined bioethical problems in contemporary healthcare. Yet conceptualizations of moral distress in bioethical inquiry often overlook a range of routine threats to professional integrity in healthcare work. Using examples from our research on frontline physicians working during the COVID-19 pandemic, this article clarifies conceptual distinctions between moral distress, moral injury, and moral stress and illustrates how these concepts operate together in healthcare work. Drawing from the philosophy of healthcare, we (...) explain how moral stress results from the normal operations of overstressed systems; unlike moral distress and moral injury, it may not involve a sense of powerlessness concerning patient care. The analysis of moral stress directs attention beyond the individual, to stress-generating systemic factors. We conclude by reflecting on how and why this conceptual clarity matters for improving clinicians’ professional wellbeing, and offer preliminary pathways for intervention. (shrink)