Moral distress is a negative emotional response that occurs when physicians know the morally correct action but are prevented from taking it because of internal or external constraints. Moral distress undermines a physician's ethical integrity, leading to anger, poor job satisfaction, reduced quality of care and burnout. Scarce literature exists on the ethical aspects of moral distress in medicine. We conducted an ethical analysis of moral distress as experienced by physicians and analysed it from the literature using two predominant ethical theories: principlism and care ethics. Finally, we consider the emergence of moral distress in medicine during the COVID-19 pandemic.