Contemporary society has an increasingly broad and holistic perspective on health and wellness. It is scientifically proven that thermalism perfectly combines these two aspects. It provides a better quality of life and a complete state of well-being, physically and psychologically. Several studies have been carried out over the years, reflecting a paradigm shift in the conception of thermalism establishments. For this reason, the sector's stakeholders need to be prepared and have the necessary knowledge to respond to the different needs, characteristics, and motivations of both usual and new thermal users to define better action strategies. In this context, the research's main objective is to present a literature review and content analysis on the thermalism topic, through the most recognised databases, exploring the offer, identifying its users’ profiles and pointing out some trends for the market. As a result of the analyses, the growing interest and relevance of thermalism in scientific production stand out, particularly in tourism, as a social science. There are several studies that present a direct link between thermalism and tourism activity. It is notorious that thermal activity has both a recreational and medicinal dimension, all over the world. Literature analysis has also revealed the power of thermal waters for the treatment of a wide range of diseases and health issues, related to different medical specialities. Although the more traditional thermalism is still very present, the most recent studies portray some gradual changes on the demand and supply side, with a constant adjustment of both. Particularly in the user profile, there is evidence of a rejuvenated, healthier and heterogeneous demand, with different motivations to frequent the thermal spas. On the supply side, it can be seen that these establishments are seeking to reinvent themselves in order to complement their basic offer related to medical dimension, also focusing on the leisure, to enrich the experience of their regular users and attract others. Regarding the expected trends, they are mainly related to 1) Increased demand for prevention, leisure and well-being dimension; 2) Changes in the user profile; and 3) High potential for tourism activity.