There are many links between the creatures of folklore and illnesses. Before the age of medical science diseases were thought to have been caused by ill-willed creatures/demons. The most important example in a troll context is the changeling myth where a number of diseases have been suggested as the origin of the myth, eg. Downs' syndrome and Rachitis (caused by undernourishment) and Atrepsi. The so-called "Brøndmand" or "Well Man" residing in farm wells has also been seen as related to poisoned water causing various diseases. In Norwegian language troll traditionally also refers to various diseases (e.g. lumbago) that in folklore was assumed to have been inflicted by magic.
To be continued.

Tags: troll, diseases