Aftersickness is the result of using the Secret Art or a native talent or gift. It can cause crippling pain to a mancer, though more powerful mancers are able to use Arts with little aftersickness, that minor mancers could not use at all.

Extremely powerful mancers such as Rulke and Faelamor have been known to force back aftersickness in desperate situations, however, it invariably returns at a significantly more painful level.