Colloquially referred to as The Stiffness, Prolonged Petrification refers to the phenomena where a humanoid or creature over the course of many years will find their body replaced with organic or inorganic material that interrupts normal body function. Often times the body will be replaced with stone or wood but there have been rare occasion of rarer materials. It will begin with extremities of the body taking on these new properties and will progress until the entire body is encased, once the disease has progressed this far it is only a matter of hours before all bodily functions cease and the infected is declared dead. It is a slow moving disease however and can take years or even decades to reach its final form upon infection.
Interestingly enough, most people will never come across this disease, even though evidence shows everyone is capable of contracting it. The biggest victims of this disease are people and creatures that otherwise would be deemed as "immortal." The method of contraction is currently unknown, it has proven to not be spread through usual vectors, nor does the disease seem magical in nature. It seems almost an inevitability that the older something becomes the more likely it is to be afflicted by Prolonged Petrification. The problem with this disease is that many of those affected do not realize the change as it is taking place. Often times it is only when they are in the final stages that they recognize what is happening to them.
The best way to treat Prolonged Petrification seems to be to never get it in the first place. If caught early enough intensive magical and medical treatment can reverse damage done or at the very least halt its progress. In further stages progress can only be halt. In the final stages no means, magical or otherwise are capable of halting or reversing the damage.
A small section of people have come forward claiming for the Illness to go away on its own, even in the advanded stages but none are able or willing to discuss the means at which this has been accomplished. Only one person was in the slightest bit helpful, saying only "Its about coming alive again... if your kind lived longer you would understand that. You research a thing that is already known and you ask questions that already have answers"
"No I'm not saying they do it to themselves but honestly it makes sense doesn't it? Living is all about learning new things and having new experiences. You have to figure, living as long as they do, you get into the habit of doing the same thing over and over after a while. I mean at that point, you might as well just be a statue!"