Corruption
The term "Corruption" can refer to a number of different effects from a variety of sources, each with their own severity and consequences. Most of the time, when people are speaking of Corruption, what they are really referring to is Abyssal Corruption.
Thanks to the efforts of Oleander, one of the legendary Heroes of Prophecy, it is now known that most forms of Corruption are caused by a decay or erosion of a subject's Tesseri, which then becomes replaced with other forms of Aether. While there are no known vaccines or cures for Corruption, it is now considered to be a condition that can be treated-- and even lived with, provided adequate medical surveillance, care, and resources.