Pathophysiology is a branch of study that focuses on the disordered physiological processes that cause, result from, or are associated with a disease or injury. It is a combination of two major disciplines, pathology, and physiology. Pathology is the study of the causes and effects of injuries and diseases, while physiology is the study of the human bodys systems and various functions. Pathophysiology seeks to explain the functional changes that are occurring within an individual due to a disease or pathologic state. It describes the changes that occur during a disease process, with "patho-" referring to the physical changes that are observed and "physio-" referring to the functional processes or mechanisms that occur during a disease process. Pathophysiology involves the investigation of biological processes that are directly related to disease processes of physical, mental, or psychophysiological conditions and disorders. It is formally considered as a subdiscipline within physiology. Nurses rely on pathophysiology when diagnosing acute and chronic conditions in patients, and it is one of the many areas of study in nursing school. With a firm grasp of pathophysiology and its components, nurses can properly assess a patients injury or illness and its stage of development, which leads to proper treatment and better outcomes.