The article presents a theoretical analysis of the terms most often used to describe the phenomenon of the process of complying with medical recommendations by a chronically ill person in the context of the specifi cs of the interaction that exists between a patient and a doctor. The medical phrases, such as: compliance, adherence, and especially concordance are presented in terms of their defi nitions, basic interpretations and critical comments. Moreover, two opposite theoretical models of a chronically ill person’s involvment in his/her medical treatment have been recalled in order to reveal the evolution of healthcare theory towards patient empowerment. The psychological references to communication and sociological terms of participation and deliberation have been also mentioned about.
