With the increasing prevalence rates of periodontitis cases, it has a great impact on human health, especially elderly patients. It constitutes a major health problem that can cause significant burdens. Infections are the main pathology that have been previously reported among studies in the literature because it has a strong correlation. There are common mechanisms that can cause systemic diseases: induction of systemic inflammation, inflammatory markers, the release of toxins, and translocation into other organs through the bloodstream. Proving the correlation between the potential presence of the involved pathogen and systemic diseases might be a significant key factor in predicting these systemic events. In addition, it will assist to have proper management in early intervention. The aim of the study was to provide more insight into the effect of correlation between periodontitis and other systemic diseases according to studies in the literature. Multiple organisms that can cause periodontitis have been significantly correlated with the development of many systemic diseases, such as atherosclerosis, coronary artery disease (CAD), pneumonia, respiratory tract infections, oral and colorectal cancers, diabetes and Alzheimer’s disease. Moreover, Porphyromonas gingivalis has been commonly reported with the variously discussed systemic diseases which should draw more attention towards the proper management and prevent this organism and other microbes within the literature to enhance the outcomes.