Health risk perception and individual behaviour remain central determinants of public health outcomes, particularly in low- and middle-income countries where structural constraints intersect with cultural, social, and psychological factors. This article presents an integrative, theoretically grounded analysis of health-related risk perception, sexual behaviour, and behaviour change communication, drawing strictly and comprehensively on the provided body of literature. Anchored in public health, behavioural science, and qualitative research traditions, the study synthesizes evidence on HIV/AIDS risk perception, sexual behaviour among adolescents and university students, chronic disease risk awareness, and the role of communication strategies in shaping health-related decisions. The analysis situates individual behaviour within broader socio-cultural, institutional, and policy environments, highlighting how misconceptions, stigma, gender norms, power relations, and access to information influence health outcomes. Methodologically, the article adopts an interpretive, qualitative meta-synthesis approach informed by grounded theory, content analysis, and naturalistic inquiry to examine patterns across diverse empirical contexts in Africa and other low- and middle-income settings. Findings indicate persistent gaps between knowledge and behaviour, the resilience of myths and misconceptions despite awareness campaigns, and the critical importance of culturally embedded communication strategies that move beyond information provision toward empowerment and sustained behaviour change. The discussion elaborates theoretical implications for health behaviour models, critically examines limitations within existing research, and proposes future directions for integrated, ethically grounded interventions. By offering an extensive conceptual elaboration, this article contributes to advancing scholarly understanding of health behaviour dynamics and provides a robust foundation for policy, practice, and future research in global public health.