Semiology is the general science of signs.
The word comes from the union of the Greek words seed, which means sign, and logos, study.
Semiology is an area of knowledge dedicated to understanding the meaning systems developed by society. Its object is the sets of signs, be they linguistic, visual, or even rites and customs.
A sign is the combination of the meaning and the signifier, that is, the concept with the object itself. Such as a traffic sign. It alone is just a set of visuals, colors and designs. It is from the meaning given to it that it constitutes a sign, and gains a new meaning.
Medical Semiology
Medical Semiology is a theoretical and practical discipline of Health Sciences that dedicates its pay attention to signs and symptoms presented by the patients.
During the general physical examination, non-verbal signs should be observed that will help to make a better diagnosis, in addition to the symptoms verbalized by the patients.
It is a diagnostic method developed by Henry Stubbes in 1670. The analysis considers the patient's general condition, level of consciousness, posture and signs of discomfort. There are also other elements that are not narrated, but fundamental for the diagnosis, such as the presence of edema, body odors, dry parts, and so on.
Semiotics and Semiology
The terms Semiotics and Semiology represent the same field of study, but a determination of the Association International Semiotic Studies in 1969 decided to use the term Semiotics as the name of the general science of signs.
Semiotics and Semiology were used as synonyms until then. What differentiated the two terms was the line and origin of the research: if it was associated with the North American tradition of Charles Pierce, it was Semiotics. And the European school, led by the linguistics of Ferdinand de Sassure, called semiology.
But in the second half of the 20th century, important European authors such as Roland Barthes and Umberto Eco adopted the term semiotics to designate their studies on systems of meaning. Then, at the suggestion of several researchers, the Association opted for the exclusive use of the term semiotics.
But the decision does not invalidate previous studies in semiology. Just standardize the field.