This book is composed of twenty-one chapters that can be further divided into four parts: (i) A brief introduction to pathophysiology and the disease. (ii) The cellular and molecular pathophysiology including deregulation of signal transduction and mechanisms underlying aberrant cell proliferation, differentiation and death. (iii) The fundamental pathological processes that can appear in different diseases, including fluid and electrolyte imbalance, acid and base disturbance, glucose metabolism disorder, lipid metabolism disorders, stress, fever, edema, ischemia and reperfusion, shock, multi-organic dysfunction, and hypoxia. Knowledge of these basic pathophysiological processe is essential for understanding the general mechanisms underlying most of the diseases. (iv) The organ dysfunctions including heart, lung, liver, kidney and the brain. The focus in his last part is still on the pathological processes and the mechanisms underlying the organ insufficiency or failure. Each chapter is organized by the segments emphasizing respectively the general concepts, the etiology and pathogenesis, the alterations of metabolism and the function, and as well as the principles for the prevention and therapies, which are also the key for teaching and learning in pathophysiology courses.The clinical doctors can choose the book as a refresher and update their understanding the mechanisms of diseases. Nurses and other practitioners will find that the concise format and broad/new scope of the book facilitate their understanding of basic disease entities.