Semiotics and Semiology share a similar etymology and meaning:

the study of signs. In Medicine, signs are objective manifestations of disease, as opposed to the subjective nature of symptoms. Medical semiology comprises the study of symptoms, somatic signs and laboratory signs, history taking and physical examination (in English-speaking countries is known as Bedside diagnostic examination or Physical diagnosis). The first edition of Medical Semiology dates from 1987, and new editions appeared in 1999, 2010, and 2017. The book is devoted to semiology proper with clinical orientation. Its origin, however, dates back to 1937, when the University of Chile appointed Dr. Hernán Alessandri (1900-1981), the eminent Chilean medical educator, Professor in Semiology at the Internal Medicine Section of the Hospital del Salvador in Santiago. The authors of the present book served as Dr. Alessandri's teaching assistants for decades. The two-semester course in semiology had a tutorial character: each teaching assistant was assigned five students whom engaged daily in practical activities in the hospital wards for a total of four hours, in addition to a 45- minute lecture on the theoretical aspects of the subject. The 720-page fourth edition of the book brings together teaching method and clinical experience of more than 50 years.

The book consists of six Sections:

"Cardinal manifestations of disease", "Major clinical syndromes", "History taking and Physical examination", "Clinical diagnosis and the patient-physician relationship", "Laboratory clinical tests and Instrumental exploration of the body," and "Glossary of diseases." In its forty Chapters, a total of 207 issues are described in detail.