Etiology

Etiology, also referred to as aitiology, aetiology, and disorder etiology, is study or theory of the factors that cause diseases or disorders; what is called causation. It also involves the origin of diseases and the methods by which diseases inflict a host such as a human. More specifically, etiology, in medicine, is the sum of knowledge regarding a disease, or knowledge of all pathological processes leading to a disease. In the process of etiology, there may be just one causative agent, but no one specific cause of disease.

The term etiology is derived from the Greek word aitiologia, which means statement of a cause. In the modern medical language, physicians may state that the ‘etiology is unknown’; that is, the cause of the problem is not known. Etiology is also used in such scientific fields as biology, chemistry, physics, and psychology.

As an example of how etiology is used in the medical field, medical scientists know that tuberculosis is caused by the tubercle bacillus. Many people are exposed to the tubercle bacillus yet only one may develop the disease. The bacilli can also lay dormant in the body for many years and became active as the result of an intercurrent infection (occurring during the course of an existing disease), prolonged stress, or starvation.

While some diseases have no known cause, there are several factors that may contribute to, or predispose someone to a disease. Many variables must be considered when looking at the cause of a disease such as, gender, age, environment, lifestyle, heredity, allergy, immunity, and exposure.