How and why do we measure surgical risk?

Surgical decision-making has evolved over time, and what was once an intuitive matter for surgeons has now become a multi-faceted decision with increased expectations from medical staff and patients, making the decision-making process itself often as challenging as the technical procedure. When planning the most appropriate treatment for a patient, it is important to distinguish what we aim to achieve with regards to treating the pathology from what can be realistically expected from the patient physiologically. In other words, has the patient the potential to withstand the insult of the treatment itself and what are the risks involved? By quantifying this risk and making it a key part of surgical decision-making, we can arrive at the safest modality of treatment for an individual patient. This allows realistic expectations for the patient, helping them to make an informed decision. This article aims to highlight some of the important aspects of surgical risk and the impact they have on patients.