Microcirculation reflects the vascular bridge which is the conduit of blood flow between the arteries and veins in the body. It plays a critical role in the delivery of oxygen and nutrients to the cells of the body while also serving to wash away and eliminate biological waste products of metabolism. A complex interplay exists between the normal structure and function of the larger vessels of the body and the blood coursing through. This book discusses the evolving science in understanding the role of microcirculation in some of the most common and devastating diseases that plague humanity. By understanding the role of microcirculation in the normal feedback mechanisms that balance bleeding and clotting with the opportunities to manipulate this balance to treat disease, the impact on the individual and social burden of arterial and venous occlusive and thromboembolic disease can be substantial. Understanding disease mechanisms and enhancing our collective tools for diagnosis and treatment are some of the greatest challenges facing our global healthcare systems. The chapters in this book serve as a foundation for further research into the quest to reduce, if not eliminate, one of the most significant causes of major morbidity, mortality, and overall loss of quality of life worldwide. Without a doubt, the impact of the body's microcirculation, as our understanding continues to evolve and as emphasized in this text, cannot and should not be underappreciated.