Healthy Thanks to Communication: A Model of Communication Competences to Optimize Health Literacy – Assertiveness, Clear Language and Positivity Célia Belim School of Social and Political Sciences – University of Lisbon (ISCSP-ULisboa), Portugal Cristina Vaz de Almeida School of Social and Political Sciences – University of Lisbon (ISCSP-ULisboa), Portugal ABSTRACT This chapter focuses on the contribution of communication competences, used by healthcare professionals in the clinical relationship with patients, to improve therapeutic adherence through a better understanding of health instructions and, hence, higher competences in health literacy. It is a main goal to construct a model of communication competences that includes the interdependent use of assertiveness, clear language and positivity by the healthcare professional. The research of an exploratory nature is based on the literature review and on the focus group, used to obtain validation of the model by specialists. The focus group is composed by Portuguese medical doctors, nurses and specialized professors on health literacy. Operationalizing the model and decomposing the three key concepts/variables of the model, the participants of focus group validate the model and most punctuate, in assertiveness, active behavior, ability to listen and ability to openly speak; in clarity, the simple language, utilization of verbs; and, in positivity, orientation to a positive behavior of the patient. The results confirm that the investment in the communication competences by the health professional is reflected in the optimization of the results on the health literacy of the patient. Concretely, assertiveness, clear language and positivity are pivotal and strategic elements to the optimization of health literacy and clinical practices, recognized in the literature and by the participants in the focus group. Keywords: Health Communication, Therapeutic Relationship, Health Professionals, Patients INTRODUCTION Communication is a sine qua non for human life and social order (Watzlawick, Beavin & Jackson, 1967) and all communication affects human behavior (Watzlawick et al., 1967). Communication competences are vital to the optimization of therapeutic relationship (e.g. Silverman, Krutz & Draper, 2013; Van't Jagt, de Winter, Reijneveld, Hoeks & Jansen, 2016) and of the health literacy due to better health results are based on the ability to communicate with patients (e.g. Benson, 2014, p.