Book excerpt: Micro and Nano Flow Systems for Bioanalysis addresses the latest developments in biomedical engineering at very small scales. It shows how organic systems require multi-scale understanding in the broadest sensewhether the approach is experimental or mathematical, and whether the physiological state is healthy or diseased. Micro-and nano-fluidics represent key areas of translational research in which state-of-the-art engineering processes and devices are applied to bedside monitoring and treatment. By applying conventional micro- and nano-engineering to complex organic solids, fluids, and their interactions, leading researchers from throughout the world describe methods and techniques with great potential for use in medicine and clinical practice. Coverage includes the seeming plethora of new, fine-scale optical methods for measuring blood flow as well as endothelial activation and interaction with tissue. Generic areas of modeling and bioelectronics are also considered. In keeping with the recurring theme of medicine and clinical practice, approximately half of the chapters focus on the specific application of micro- and nano- flow systems to the understanding and treatment of cancer and cardiovascular diseases. This book developed from an Expert Overview Session on "Micro & Nano Flows in Medicine: the way ahead" at the 3rd Micro and Nano Flows Conference (MNF2011) held in Thessaloniki, Greece. Additional chapters were included to enhance the international, state-of-the-art coverage.