It should come as no surprise to the reader that the oral cavity, including the periodontal tissues, are not somehow disjointed from the rest of the body. In this paper, we will explore the links between the periodontal and general health of our patients in both directions. That is to say we will explore how someone's general or systemic health conditions/habits are likely to affect their periodontal health, and how someone's periodontal health is likely to affect their systemic health. Before exploring these links, we will discuss the distinction between an association and a causal relationship, which is a subtle but vital distinction to make. We will then discuss the role of systemic conditions/habits such as diabetes, smoking, diet and stress on the periodontal health of individuals. Following from this, we will discuss the potential influence of the periodontal health of our patients on their systemic health, focussing on the more established links with diabetes and cardiovascular diseases as well as exploring the mechanisms by which these links may exist. We will conclude with some tips on the holistic care of our patients, incorporating changes that will benefit their oral and systemic health.