Johannes Hoffer coined term Nostalgia in 1688 in his medical dissertation.
Nostalgia was a formal medical diagnosis, and one that dates back to 17th century when soldiers had longing for home and melancholy with a constellation of symptoms including lethargy, sadness, disturbed sleep, heart palpitations, GI complaints, and/or skin findings for which the only cure was to return home.
In the civil war, over 5000 soldiers were given medical leave for nostalgia.
Always remember to view your patient in the appropriate context (psychosocial, cultural, historical, etc.)
Beck, J. (2013, August 14). When Nostalgia Was a Disease. Retrieved March 08, 2018, from https://www.theatlantic.com/health/archive/2013/08/when-nostalgia-was-a-disease/278648/