Health literacy is essential for promoting well-being and the ability to make informed decisions. We investigated the level of health literacy in Brazil and identified the predictive factors that influence it. Our data contribute to the international context, with a focus on countries in the Global South and, in particular, Latin America. By analyzing health literacy in Brazil, this study sheds light on the challenges faced by populations with similar socioeconomic backgrounds in low- and middle-income countries, where disparities in access to education and health services are widespread. In addition to descriptive analysis, we used the Random Forest machine learning algorithm, which uses bootstrap aggregation (bagging). To make the results interpretable, we implemented Shapley’s Additive exPlanation values. The results show a predominance of problematic levels of health literacy among the population. The analysis reveals that factors such as medication use, dependence on the Unified Health System (Sistema Único de Saúde), and educational level are significant predictors of health literacy. The findings highlight the need for public policies aimed at reducing socioeconomic disparities and improving the public health system in order to promote better access to and understanding of health information.

Background: Climate change, marked by extreme events such as droughts and floods, profoundly affects mental health, leading to climate anxiety, characterized by fear and worry about its effects, which can also adversely impact sustainability. Objective: To explore the socioeconomic and psychological factors influencing the levels of climate anxiety measured by the Climate Change Anxiety Scale (CCAS). Methodology: Systematic literature review following PRISMA guidelines, analyzing studies from various regions, focusing on empirical data using CCAS and other complementary instruments. Results: Young individuals and those with greater exposure to climate change report higher levels of anxiety, often associated with symptoms of depression and stress. Although anxiety can drive pro-environmental and sustainable behaviors, it can also lead to ecoparalysis in some individuals. Conclusions: The CCAS is an effective tool to measure climate anxiety and has the potential to identify vulnerable groups facing the climate crisis. This study highlights the importance of specific interventions to address the psychological impacts of climate change, and promote public policies focusing on sustainability issues.