The study of phenomena that occur during sleep has always aroused a great interest in various fields of human knowledge, both in religion and in philosophy, as well as in science. Hippocrates and Aristotle conducted different studies and observations on sleep and dreams, focusing on the changes that affect the state of consciousness between the waking and sleeping states. Freud even started from the observations and interpretation of dreams in the foundation of the psychoanalytic method. After the introduction of the electroencephalogram (EEG) by Hans Berger (1929), the beginning of modern sleep medicine began.
Currently, the scientific literature in this field is very vast, gathering different aspects of many medical specialties, mainly including psychiatry, neurology, pneumology, cardiology, internal medicine, and others. Precisely because of this broad extension, it is not completely explorable by clinicians and is not always adequate for their needs.