Microcirculation is the most basic structure of the circulatory system. It is the main location for material exchange between blood and tissues. Blood microcirculation refers to blood circulation in the capillaries between arterioles and venules. Microcirculation disorders are one of the important pathophysiological bases of chronic diseases. Improving microcirculation disorders is of great significance for the prevention, delay, and treatment of various chronic diseases. For instance, there is a need to focus on studying the mechanism of microcirculation disorders in chronic diseases, such as analyzing clinical manifestations and focusing on the clinical evidence and principles for improving microcirculation disorders. Studying microvessel structure and microvascular alterations as biomarkers can provide a certain reference for clinicians to rationally choose drugs to improve microcirculation disorders in chronic diseases. New clinical evidence can help with the treatment of chronic disease microcirculation disorders.

Many chronic diseases (e.g., diabetes, hypertension, glaucoma) are related to microcirculation disorders. Monitoring the changes of microcirculation is helpful to clinically understand the occurrence and development of diseases and the prognosis of treatment. Common surface microcirculation measuring instruments mainly include nailfold microcirculation electron microscope, laser scanning Doppler blood flow meter, television (TV) microscope, etc. These inspections are noninvasive and can be used to monitor and follow up on chronic diseases. It helps clinicians treat microcirculation disorders in patients. Moreover, it provides early diagnosis, early prevention, and treatment in clinical practice. Early treatment improves the prognosis of chronic diseases. However, ways for improving microcirculation disorders are still lacking sufficient evidence-based medical evidence. More basic research and related large-scale prospective clinical studies are still needed in the future to improve clinical applications.

The aim of this Special Issue is to bring together original research and review articles that discuss microvessel structure and microvascular alterations in chronic diseases.

Potential topics include but are not limited to the following:

• Microvessel structure in chronic diseases
• Microvascular alterations in chronic diseases
• Underlying mechanisms of microvascular alterations
• Biomarkers or specific signs for chronic microvascular alterations
• Novel examinations in microvessels
• Microvascular alterations before and after medical treatment
• Novel treatments based on examining microvascular alterations in chronic diseases