Health literacy (HL) refers to the ability of individuals to obtain, interpret, evaluate, and use health information effectively. It is a broad and multidimensional construct shaped by demographic, cultural, social, and systemic determinants. Inadequate HL is strongly linked to negative health outcomes, limited utilization of preventive services, higher rates of hospital admissions, and elevated healthcare costs. Research indicates that low levels of HL particularly affect vulnerable groups such as older adults, minority populations, and individuals with limited education or low income. Primary care physicians and other healthcare providers play a vital role in improving HL by integrating educational and supportive strategies into routine care. Furthermore, improving health literacy requires the active participation of many stakeholders, including public agencies, educators, the media, and civil society organizations. This review highlights the importance of prioritizing HL improvement as a public health strategy to advance equity in healthcare access and to diminish health inequalities.