The ability of doctors to empathise with patients is a crucial concern in establishing humanistic medicine. Therefore, the cultivation of this ability has been discussed extensively in medical education. One theory suggests that the experience of patienthood can increase empathy among doctors. This theory is supported by previous research that published doctors' illness narratives. However, the concept of empathy has been ambiguously defined in academic fields, including medicine; therefore, analysing how doctors experience 'empathy' in their interactions with patients is difficult. Our research question is how doctors who became patients describe the relationship between their illness experiences and the interactions with patients after their illness. To this end, this paper initially tracks the debates on 'empathy' in medicine and other disciplines, to develop a lens for analysing doctors' illness narratives. Next, we conduct a narrative analysis of illness stories from 18 Japanese medical doctors who became patients. Our analysis supports the traditional idea that an illness can enable a doctor to become more empathetic. However, this is overly simplistic; how doctors experience and subsequently process their illness is more complex. Moreover, this notion can disregard doctors' suffering in these circumstances, and fail to represent the often-lengthy process of mastering 'empathy' based on their experiences. Therefore, our analysis deconstructed the concept of 'empathy', showing that it can appear in various ways. Further research is required to elucidate how empathy is cultivated during the process of transformation of doctors' illnesses, focusing on their communities and practices.