Which term refers to the study of disease?

The term that refers to the study of disease is "Pathology." Pathology encompasses the investigation of the causes, effects, and nature of diseases. It involves understanding how various diseases can alter bodily functions and structures, assessing disease mechanisms, and diagnosing illnesses through the examination of tissues, cells, and body fluids.

Pathology plays an essential role in medicine, as it helps to clarify the underlying issues that contribute to a patient's condition, leading to more accurate diagnoses and treatment plans. This field serves as a bridge between basic science and clinical practice, providing critical insights into how diseases develop and progress.

The other terms may relate to aspects of healthcare or biological sciences but do not specifically pertain to the comprehensive study of disease itself. Diagnosis refers to identifying a disease based on symptoms and testing, hematology is the study of blood and blood disorders, and physiology deals with the normal functions of living organisms and their parts.