This is part of a series of lectures on Qin Bowei's 56 methods. The lecture focuses on blood and blood disorders. The lecture discusses the source, causes, mechanism, locations, disease manifestations, and presenting symptoms, in order to develop a broad picture of Blood. Associated treatment principles behind blood disorders will also be covered. The lecture will also discuss key diagnostic criteria for each principle, the associated flagship formula for each, how to modify it, as well as how it relates to classical Chinese medicine. The lecture will conclude with numerous case studies to demonstrate how the system can be used clinically.