This book on the neuroanatomical and functional aspects of pain is the result of an incessant search for knowledge in the field of health about the causes, mechanisms, neuroanatomical pathways and, ultimately, pain analgesia. The perception of pain can vary not only from one person to another, but also according to culture, being transformed by many factors. It is therefore a subjective response: each individual learns the sensation through experiences related to injuries early in life. It is therefore considered one of the main symptoms related to an individual's health.