The study of disordered physiological processes that cause, result from, or are otherwise associated with a disease or injury is called pathophysiology. It is a field of study that is formed as a result of the integration of pathology and physiology. Pathology is a medical field that explains abnormal or disease state whereas, physiology is a biological field that explains the mechanisms functioning within an organism. Thus, pathophysiology seeks to describe the functional changes that happen within an individual due to a disease or pathological state. Traumatic brain injury (TBI) occurs when the brain moves rapidly within the skull leading to damage due to an external mechanical force such as a blow, bump, or jolt. The level of impact and effect that TBI causes is different in different individuals due to the complexity of the cerebral pathophysiology involved. No two TBIs are the same because the injuries differ in severity, type and location, and the age and gender of the affected individual. All these factors lead to the development of unique brain pathologies. Both real-time, high resolution monitoring together with intermittent monitoring of injury pathophysiology are essential in the modern neuro intensive care units (NICUs). Monitoring the TBI pathophysiology helps detect deterioration, guides treatment, and may also be used to forecast the efficacy of new treatment strategies. This book contains some path-breaking studies related to the pathophysiology of the injured brain. It consists of contributions made by international experts.