The Rot

Summary
The Rot is a disease caused as an after product of years of Nuclear Radiation spreading through the entire world after the rapid creation of Nuclear Weapons around the world. It's nicknamed the Rot due to it quite literally causing the organ it's attacking to Rot away.

The Brain
The Brain Strand of the Rot attacks the brain. It starts as undetectable and is hard to notice, but as time goes on it becomes more deadly and noticable. Eventually it causes minor things like color blindness and and face recognition, then more major issues like motor problems to things like hands, feet, legs and arms ,then it causes two main outcomes: Death, what happens 98% of the time, or becoming part of the Rotten, which happens 2% of the time. The Brain Strand of the Rot is the only contagious form of the Rot and often causes the other strands to form.

The Heart
When the Rot attacks the heart, it stops the flow of blood to the human body slowly, but this can be prevented by a blood transfusion of someone who has the same blood type as does not have the Rot. If someone with the Rot gives a blood transfusion to someone with Heart Rot, their condition will be cranked to 11 and become extremely fatal, causing things like seizures and of course, heart failure.

The Eyes
The Rot within the eyes causes blindness and other smaller side effects. This is the rarest but also least dangerous strand of the Rot.