Many popular news outlets, such as The New York Times, The Washington Post, and The Atlantic, are documenting patient reports of medical gaslighting, where patients (typically female) detail their experiences of explaining their symptoms to their doctors only to be told that their illness is imagined or that their symptoms are being exaggerated. Medical scholars have also begun to discuss patient accounts of medical gaslighting. Gaslighting, more generally, has also captured the attention of philosophers such as Kate Abramson, Andrew Spear, and Cynthia Stark. In this presentation, I first show that interlocutors discussing medical gaslighting are often discussing different concepts. Patient accounts of medical gaslighting vary, ranging from a doctor’s vague dismissiveness to deliberate psychological manipulation. The few medical scholars writing on medical gaslighting also use different definitions of medical gaslighting. It is evident that there is currently no single account of what medical gaslighting is. Next, I argue that a unified account of medical gaslighting that draws from philosophy will achieve several worthy aims. I then propose such an account: medical gaslighting ought to be understood as cases where a healthcare provider manipulates his patient such that she is made to feel that she is a non-credible witness to domains over which she has first personal authority. The patient loses confidence in her own epistemic agency, and must defer to the gaslighter’s assessment of her epistemic status as a result.