Etiological

Etiological is an adjective relating to etiology, the study of the causes or origins of diseases, conditions, or phenomena. In medicine and epidemiology, etiological descriptions identify the factors that initiate a disorder or health outcome, as opposed to manifestations or symptoms alone. Etiological factors can be genetic, environmental, infectious, autoimmune, or a combination thereof. The goal of etiological work is often to establish a causal link between a factor and a disease, which can inform prevention, diagnosis, and treatment strategies. When a specific cause is identified, the diagnosis may be described as etiological or etiopathogenic, and a corresponding etiological diagnosis highlights the underlying agent or mechanism.

Examples include the etiological agent of tuberculosis, Mycobacterium tuberculosis, and the historical shift in understanding peptic ulcers from stress-related theories to Helicobacter pylori as an etiological factor. Some diseases have multifactorial etiologies, in which several interrelated factors contribute to their development. In research and public health, etiological studies may involve observational data, laboratory experiments, and mechanistic investigations to demonstrate causation, using criteria such as temporal sequence, strength of association, consistency, and experimental evidence.

Outside medicine, etiological is used in philosophy and the social sciences to discuss causal explanations and origins of phenomena beyond disease. See also etiology, etiologic agent, etiologic factor.