Background The evaluation of pain remains one of the most difficult challenges that healthcare practitioners face. Chronic pain appears to affect more than 35% of the population in the West, and indeed, pain is the most common reason patients seek medical care. Despite its ubiquity, studies in the last decades reveal that many patients feel their pain is dismissed by healthcare practitioners and that, as a result, they are denied proper medical care. Buchman, Ho, and Goldberg (J Bioethic Inq 14:31-42, 2017) point to this phenomenon as a form of "epistemic injustice": an unfair and harmful downgrading of credibility affecting some individuals and groups, which prevents them from receiving appropriate and beneficial medical care. Methods By exploring the existing literature on this downgrading of patients' credibility written by healthcare professionals and scholars in medical humanities, I identify and examine the reasons patients are often not believed about their pain and why healthcare is too-often unhelpful or hurtful to people presenting with chronic pain. I also explore to what extent it is possible to forge an alternative epistemological model. Results I suggest that most of the causes of this downgrading of patient's credibility result from either the difficulty in communicating pain or the widespread belief that pathology is always the result of objective tissue damage. I examine whether pain has to be effectively communicated and have an objective cause in order for it to be deemed credible. In the end, I argue that in the case of pain, both communication and objectivity are highly problematic. Conclusions I conclude by suggesting that, although alternative epistemological models might be impossible to build, believing patients has both moral and clinical benefits, and this warrants further research.