This article conveys how taking patient knowledge seriously can improve patient experience and further medical science. In clinical contexts related to infection-associated chronic conditions and other complex chronic illnesses, patient knowledge is often undervalued, even when clinicians have limited training in diagnosing and treating a particular condition. Despite growing acknowledgement of the importance of patients as ‘stakeholders’, clinicians and medical researchers have yet to fully develop ways to evaluate and, when appropriate, meaningfully incorporate patient knowledge—experiential, scientific, social scientific, historical or otherwise—into clinical practice and research. We argue that there are opportunities for clinicians and researchers to collaborate with patients and colleagues from the social sciences and humanities. We use two examples to demonstrate why patient knowledge should inform medical engagement with chronic and complex conditions. The first comes from a disability studies scholar who describes the social biases that can sideline patient expertise, and the second is from an anthropologist whose reading in medical humanities led to an effective treatment for her recovery. Rather than merely acknowledging ‘lived experience’, clinical and research teams should include patients with complex chronic conditions as ‘knowledge partners’. These patients occupy unique and valuable epistemological positions, and their knowledge should be considered with as much openness and rigour as other forms of medical knowledge. As more medical schools, residency programmes and hospitals emphasise the need for ‘deep listening’ and patient input, we encourage meaningful engagement with patients whose insights can provide crucial knowledge for clinical and scientific advancement.