Allogeneic blood transfusion has had a central role in the development and practice of numerous medical and surgical advances. In recent years, transfusion has no longer been regarded as essential for the management of a wide range of diseases and most uncomplicated elective surgeries in well-prepared patients should now be conducted without the use of transfusions. With the exception of chronic haematopoietic deficiencies, the 'transplantation' of allogeneic blood is usually supportive therapy and is generally only required in relationship to complicated major surgery, trauma and until the basic disease processes can be corrected. For most patients it is possible to minimise or avoid blood transfusion by a 'standard of care' management of a patient's own blood by optimising and preserving haematopoietic reserves in conjunction with tolerating the effects of deficiencies. The corollary to avoiding blood transfusion is that potential transfusion hazards need not be considered. This article focusses on the three-pillar matrix of patient blood management. The understanding of basic physiology and pathophysiology is at the core of evidence-based approaches to optimising erythropoiesis, minimising bleeding and tolerating anaemia.