The etymology of the term etiology takes us to the Greek word aitiologia . At a general level, it can be said that etiology is the study of the causes of something .
The notion is usually used in the field of medicine to refer to the study of the causes of diseases . Etiology, in this framework, analyzes the origin of health disorders, investigating the factors that produce them.
Currently, it is understood that a disease needs three factors to develop: a host (the organism that becomes ill), an agent (that which causes discomfort or damage) and an environment (the environment). The three factors, according to the etiology, must be concurrent in space and time for the disease to manifest.
A virus , a bacteria , a fungus or a parasite , to name a few possibilities, can act as agents, affecting a human being (the host) who is in a certain area. Once the disease is present in the person, it is important to turn to the etiology to know its causes since this information helps define the treatment.
Etiology also recognizes that factors can be facilitating , predisposing , enhancing or triggering . Depending on sex, age , living conditions and nutrition, an individual may have a greater or lesser probability of contracting certain diseases.
Already in the time of Hippocrates of Cos , an important Greek doctor who lived in the century of Pericles, doctors asked their patients three key questions to begin the preparation of the medical history :
* What's wrong with you?
* Since when?
* What do you think is the reason?
In other words, the doctor gives the patient the opportunity to express his opinion about the cause of his discomfort. In the 19th century, the chemist Louis Pasteur and the biologist Claude Bernard , both natives of France, represented two points of view that medicine had been studying for a long time: the cause of a disease is a single factor; The cause arises from several factors that act simultaneously.
In this way the basis of etiology was forged, which like all human creations went through different stages. Bernard focused on environmental, internal and external factors; His theory argued that the disease arose from having lost internal balance, something that usually occurs due to a long list of factors.
For his part, Pasteur dedicated his efforts to discovering what role bacteria played in the appearance of a disease, and to do so he related several diseases to certain microbes. His theories were widely accepted because he was able to demonstrate several of these relationships.
This discussion, which laid the foundations of etiology, leaned in favor of Pasteur, and in this way doctors began to accept that diseases are caused by specific microbes. A German scientist named Heinrich Hermann Robert Koch was the one who formulated the concept of scientific etiology, properly speaking.
Biology advanced greatly during the 19th century thanks to the development of technology focused on medicine, which led to the creation of diagnostic instruments such as the stethoscope and devices to measure blood pressure, in addition to promoting the sophistication of surgery. This growth collaborated with the definition of etiology, since it gave doctors more tools to find the causes of diseases, without forgetting that it also enhanced the effectiveness of treatments.
It is important not to confuse etiology with ethology : the latter term refers to the specialty of biology that is dedicated to studying how animals behave.