Periodontal disease is one of the most prevalent chronic inflammatory conditions affecting the supporting structures of the teeth. Increasing evidence suggests that periodontal disease extends beyond the oral cavity and contributes significantly to systemic health conditions through complex inflammatory and microbial pathways. Chronic periodontitis has been associated with cardiovascular disease, diabetes mellitus, adverse pregnancy outcomes, respiratory diseases, rheumatoid arthritis, chronic kidney disease, Alzheimer's disease, and metabolic syndrome. The biological mechanisms underlying these associations include systemic inflammation, bacteremia, immune dysregulation, oxidative stress, and endothelial dysfunction. This review examines the current understanding of the relationship between periodontal disease and systemic health, emphasizing pathophysiological mechanisms, epidemiological evidence, clinical implications, and future directions. The findings support the concept that periodontal health is an integral component of overall health and highlight the importance of interdisciplinary healthcare approaches. Improved periodontal management may contribute to better systemic health outcomes and reduced disease burden globally.