This paper delves into Charles S. Peirce's conception of the symptom, examining it through the lens of the patient-doctor relationship. It draws attention to the dichotomy presented by traditional interpretations of Peirce's model of the symptom—as either natural, thus indexical (Kathryn V. Staiano), or conventional, thus symbolic (Umberto Eco)—which inherently define the symptom as a sign per se, thus obscuring the dynamic interplay between indexicality and symbolicity as outlined in Peirce's 1904 correspondence with Lady Welby (CP 8.335). Consequently, the paper focuses on the dual nature of the symptom, a concept later elaborated within the field of medical semiotics to depict the relationship between patient and physician. Considered within a biomedical paradigm (Michel Foucault, Roland Barthes), the symptom acquires a subjective status from the patient's perspective and an objective (thus implicitly ontologically real) status from the physician's viewpoint. Hence the challenge of comprehending the symptom as a cohesive phenomenon. By discussing the biosemiotic model of symptom defined by Thure von Uexküll this paper asserts that CP 8.335 offers a self-consistent, non-reductionist, cohesive model of symptom. Firstly, it exposes the dynamics of indexicality-simbolicity in the pacient-physician relationship. Secondly, this paper reveals how the division subjective versus objective could be replaced by description of symptom in terms of the universal categories (Firstness, Secondness, Thirdness). Thirdly, it demonstrates the relevance of symptom to understanding Peirce's concept of reality.