This book focuses on the etiology of most heart diseases, and illuminates the logical etiology of modern cardiovascular diseases such as coronary heart disease and hypertension according to the main principles of general system theory. This book proposes a research method, which is consistent with systematic theory and complete inductive reasoning for cardiac, function research and addresses the ischemic causes and common psychological causes of cardiovascular disease. It also puts forward the new concepts and arguments of functional medicine, and tries to establish a unified functional medical clinical model with purpose of exploring a new way to fully prevent cardiovascular disease.