How does pathophysiology differ from physiology?

Physiology and pathophysiology are two very specific but interconnected disciplines of biology. The main difference between the two is that physiology is the study of how things work biologically in the body while pathophysiology focuses on how things work when things go wrong in the body. 

Physiology studies the numerous biological components and mechanisms of living organisms and how they function under normal circumstances.  The study involves multiple levels from cellular and tissue levels to organ and organ system levels. 

Pathophysiology combines pathology (the study of disease) and physiology to determine the interaction between disease and physiology and analyze the dysfunction of an organism as it relates to disorder, injury, or disease.