In 1688, a Swiss milkmaid was one of the first people diagnosed with nostalgia, a sickness defined by a yearning for a distant place. This intense homesickness, according to the doctor Johannes Hofer, was dangerous and potentially fatal if left untreated. Hofer prescribed remedies such as dietary adjustments and warm baths, along with outdoor exercise and pleasant conversation. The malady, primarily affecting young people, could only be resolved by a return to the victim’s homeland. Over time, nostalgia spread beyond Switzerland, becoming more deadly and common in various countries. Although nostalgia no longer poses a physical threat, it continues to hold emotional significance and is used as an explanation for perceived irrational behavior.
https://www.historytoday.com/archive/history-matters/when-nostalgia-was-deadly