Etiology

Aetiology (from the Latin aetiologia, which is derived from the Greek "aitiologia" meaning cause) actually refers to the study of causes, i.e. "the theory of causes". The term is primarily used in medicine, but also in clinical psychology and epidemiology. In medicine, it deals with the factors that lead to the development of a disease. These causes can be diverse and are often divided into three categories:

• Exogenous influences (infections, environmental factors e.g. pollutants, lifestyle factors e.g. smoking)
• Endogenous causes (genetic factors, hormonal disorders, autoimmune diseases)
• Psychosocial causes (psychological or social stress)

Aetiology plays a central role in medicine, as a causal understanding of the causes of disease is essential for diagnosis, treatment and prevention.

While etiology examines the cause of a disease, pathogenesis deals with the biological, biochemical and physiological processes that take place in an organism and ultimately lead to the symptoms or the disease.