Etiology
Etiology (/ˌiːtiˈɒlədʒi/; alternatively spelled aetiology or ætiology) is the study of causation or origination. The word is derived from the Greek word αἰτιολογία (aitiología), meaning "giving a reason for" (from αἰτία (aitía) 'cause', and -λογία (-logía) 'study of').[1] More completely, etiology is the study of the causes, origins, or reasons behind the way that things are, or the way they function, or it can refer to the causes themselves.[2] The word is commonly used in medicine (pertaining to causes of disease) and in philosophy, but also in physics, biology, psychology, government, geography, spatial analysis and theology in reference to the causes or origins of various phenomena.
Not to be confused with Etymology, Ethology, Ethnology, or Entomology.In the past, when many physical phenomena were not well understood or when histories were not recorded, myths often arose to provide etiologies. Thus, an etiological myth, or origin myth, is a myth that has arisen, been told over time or written to explain the origins of various social or natural phenomena. For example, Virgil's Aeneid is a national myth written to explain and glorify the origins of the Roman Empire. In theology, many religions have creation myths explaining the origins of the world or its relationship to believers.
In medicine, the etiology of an illness or condition refers to the frequent studies to determine one or more factors that come together to cause the illness. Relatedly, when disease is widespread, epidemiological studies investigate what associated factors, such as location, sex, exposure to chemicals, and many others, make a population more or less likely to have an illness, condition, or disease, thus helping determine its etiology. Sometimes determining etiology is an imprecise process. In the past, the etiology of a common sailor's disease, scurvy, was long unknown. When large, ocean-going ships were built, sailors began to put to sea for long periods of time, and often lacked fresh fruit and vegetables. Without knowing the precise cause, Captain James Cook suspected scurvy was caused by the lack of vegetables in the diet. Based on his suspicion, he forced his crew to eat sauerkraut, a cabbage preparation, every day, and based upon the positive outcomes, he inferred that it prevented scurvy, even though he did not know precisely why. It took about another two hundred years to discover the precise etiology; the lack of vitamin C in a sailor's diet.
The following are examples of intrinsic factors: