Blood Macro- and Microcirculation presents, in a pedagogical way, the tremendous recent progress achieved in the field of blood flow at both micro and macroscales, and with increasing complexities integrating physical, chemical and biological factors. It constitutes a unique backup of idea evolutions from the early 19th century to present day, along with the tremendous, recent progresses in experiments and simulations. Future challenges are also covered, constituting a plethora of major questions spanning the spectrum of fundamental and applied blood flow science.